pragma solidity ^0.5.16;


/*

ORACLIZE_API

Copyright (c) 2015-2016 Oraclize SRL
Copyright (c) 2016 Oraclize LTD

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

*/
// Incompatible compiler version - please select a compiler within the stated pragma range, or use a different version of the oraclizeAPI!
// Dummy contract only used to emit to end-user they are using wrong solc
contract solcChecker {
/* INCOMPATIBLE SOLC: import the following instead: "github.com/oraclize/ethereum-api/oraclizeAPI_0.4.sol" */ function f(bytes calldata x) external;
}

contract OraclizeI {

    address public cbAddress;

    function setProofType(byte _proofType) external;
    function setCustomGasPrice(uint _gasPrice) external;
    function getPrice(string memory _datasource) public returns (uint _dsprice);
    function randomDS_getSessionPubKeyHash() external view returns (bytes32 _sessionKeyHash);
    function getPrice(string memory _datasource, uint _gasLimit) public returns (uint _dsprice);
    function queryN(uint _timestamp, string memory _datasource, bytes memory _argN) public payable returns (bytes32 _id);
    function query(uint _timestamp, string calldata _datasource, string calldata _arg) external payable returns (bytes32 _id);
    function query2(uint _timestamp, string memory _datasource, string memory _arg1, string memory _arg2) public payable returns (bytes32 _id);
    function query_withGasLimit(uint _timestamp, string calldata _datasource, string calldata _arg, uint _gasLimit) external payable returns (bytes32 _id);
    function queryN_withGasLimit(uint _timestamp, string calldata _datasource, bytes calldata _argN, uint _gasLimit) external payable returns (bytes32 _id);
    function query2_withGasLimit(uint _timestamp, string calldata _datasource, string calldata _arg1, string calldata _arg2, uint _gasLimit) external payable returns (bytes32 _id);
}

contract OraclizeAddrResolverI {
    function getAddress() public returns (address _address);
}

/*

Begin solidity-cborutils

https://github.com/smartcontractkit/solidity-cborutils

MIT License

Copyright (c) 2018 SmartContract ChainLink, Ltd.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

*/
library OraclizeBuffer {

    struct buffer {
        bytes buf;
        uint capacity;
    }

    function init(buffer memory _buf, uint _capacity) internal pure {
        uint capacity = _capacity;
        if (capacity % 32 != 0) {
            capacity += 32 - (capacity % 32);
        }
        _buf.capacity = capacity; // Allocate space for the buffer data
        assembly {
            let ptr := mload(0x40)
            mstore(_buf, ptr)
            mstore(ptr, 0)
            mstore(0x40, add(ptr, capacity))
        }
    }

    function resize(buffer memory _buf, uint _capacity) private pure {
        bytes memory oldbuf = _buf.buf;
        init(_buf, _capacity);
        append(_buf, oldbuf);
    }

    function max(uint _a, uint _b) private pure returns (uint _max) {
        if (_a > _b) {
            return _a;
        }
        return _b;
    }
    /**
      * @dev Appends a byte array to the end of the buffer. Resizes if doing so
      *      would exceed the capacity of the buffer.
      * @param _buf The buffer to append to.
      * @param _data The data to append.
      * @return The original buffer.
      *
      */
    function append(buffer memory _buf, bytes memory _data) internal pure returns (buffer memory _buffer) {
        if (_data.length + _buf.buf.length > _buf.capacity) {
            resize(_buf, max(_buf.capacity, _data.length) * 2);
        }
        uint dest;
        uint src;
        uint len = _data.length;
        assembly {
            let bufptr := mload(_buf) // Memory address of the buffer data
            let buflen := mload(bufptr) // Length of existing buffer data
            dest := add(add(bufptr, buflen), 32) // Start address = buffer address + buffer length + sizeof(buffer length)
            mstore(bufptr, add(buflen, mload(_data))) // Update buffer length
            src := add(_data, 32)
        }
        for(; len >= 32; len -= 32) { // Copy word-length chunks while possible
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }
        uint mask = 256 ** (32 - len) - 1; // Copy remaining bytes
        assembly {
            let srcpart := and(mload(src), not(mask))
            let destpart := and(mload(dest), mask)
            mstore(dest, or(destpart, srcpart))
        }
        return _buf;
    }
    /**
      *
      * @dev Appends a byte to the end of the buffer. Resizes if doing so would
      * exceed the capacity of the buffer.
      * @param _buf The buffer to append to.
      * @param _data The data to append.
      * @return The original buffer.
      *
      */
    function append(buffer memory _buf, uint8 _data) internal pure {
        if (_buf.buf.length + 1 > _buf.capacity) {
            resize(_buf, _buf.capacity * 2);
        }
        assembly {
            let bufptr := mload(_buf) // Memory address of the buffer data
            let buflen := mload(bufptr) // Length of existing buffer data
            let dest := add(add(bufptr, buflen), 32) // Address = buffer address + buffer length + sizeof(buffer length)
            mstore8(dest, _data)
            mstore(bufptr, add(buflen, 1)) // Update buffer length
        }
    }
    /**
      *
      * @dev Appends a byte to the end of the buffer. Resizes if doing so would
      * exceed the capacity of the buffer.
      * @param _buf The buffer to append to.
      * @param _data The data to append.
      * @return The original buffer.
      *
      */
    function appendInt(buffer memory _buf, uint _data, uint _len) internal pure returns (buffer memory _buffer) {
        if (_len + _buf.buf.length > _buf.capacity) {
            resize(_buf, max(_buf.capacity, _len) * 2);
        }
        uint mask = 256 ** _len - 1;
        assembly {
            let bufptr := mload(_buf) // Memory address of the buffer data
            let buflen := mload(bufptr) // Length of existing buffer data
            let dest := add(add(bufptr, buflen), _len) // Address = buffer address + buffer length + sizeof(buffer length) + len
            mstore(dest, or(and(mload(dest), not(mask)), _data))
            mstore(bufptr, add(buflen, _len)) // Update buffer length
        }
        return _buf;
    }
}

library CBOR {

    using OraclizeBuffer for OraclizeBuffer.buffer;

    uint8 private constant MAJOR_TYPE_INT = 0;
    uint8 private constant MAJOR_TYPE_MAP = 5;
    uint8 private constant MAJOR_TYPE_BYTES = 2;
    uint8 private constant MAJOR_TYPE_ARRAY = 4;
    uint8 private constant MAJOR_TYPE_STRING = 3;
    uint8 private constant MAJOR_TYPE_NEGATIVE_INT = 1;
    uint8 private constant MAJOR_TYPE_CONTENT_FREE = 7;

    function encodeType(OraclizeBuffer.buffer memory _buf, uint8 _major, uint _value) private pure {
        if (_value <= 23) {
            _buf.append(uint8((_major << 5) | _value));
        } else if (_value <= 0xFF) {
            _buf.append(uint8((_major << 5) | 24));
            _buf.appendInt(_value, 1);
        } else if (_value <= 0xFFFF) {
            _buf.append(uint8((_major << 5) | 25));
            _buf.appendInt(_value, 2);
        } else if (_value <= 0xFFFFFFFF) {
            _buf.append(uint8((_major << 5) | 26));
            _buf.appendInt(_value, 4);
        } else if (_value <= 0xFFFFFFFFFFFFFFFF) {
            _buf.append(uint8((_major << 5) | 27));
            _buf.appendInt(_value, 8);
        }
    }

    function encodeIndefiniteLengthType(OraclizeBuffer.buffer memory _buf, uint8 _major) private pure {
        _buf.append(uint8((_major << 5) | 31));
    }

    function encodeUInt(OraclizeBuffer.buffer memory _buf, uint _value) internal pure {
        encodeType(_buf, MAJOR_TYPE_INT, _value);
    }

    function encodeInt(OraclizeBuffer.buffer memory _buf, int _value) internal pure {
        if (_value >= 0) {
            encodeType(_buf, MAJOR_TYPE_INT, uint(_value));
        } else {
            encodeType(_buf, MAJOR_TYPE_NEGATIVE_INT, uint(-1 - _value));
        }
    }

    function encodeBytes(OraclizeBuffer.buffer memory _buf, bytes memory _value) internal pure {
        encodeType(_buf, MAJOR_TYPE_BYTES, _value.length);
        _buf.append(_value);
    }

    function encodeString(OraclizeBuffer.buffer memory _buf, string memory _value) internal pure {
        encodeType(_buf, MAJOR_TYPE_STRING, bytes(_value).length);
        _buf.append(bytes(_value));
    }

    function startArray(OraclizeBuffer.buffer memory _buf) internal pure {
        encodeIndefiniteLengthType(_buf, MAJOR_TYPE_ARRAY);
    }

    function startMap(OraclizeBuffer.buffer memory _buf) internal pure {
        encodeIndefiniteLengthType(_buf, MAJOR_TYPE_MAP);
    }

    function endSequence(OraclizeBuffer.buffer memory _buf) internal pure {
        encodeIndefiniteLengthType(_buf, MAJOR_TYPE_CONTENT_FREE);
    }
}

/*

End solidity-cborutils

*/
contract usingOraclize {

    using CBOR for OraclizeBuffer.buffer;

    OraclizeI oraclize;
    OraclizeAddrResolverI OAR;

    uint constant day = 60 * 60 * 24;
    uint constant week = 60 * 60 * 24 * 7;
    uint constant month = 60 * 60 * 24 * 30;

    byte constant proofType_NONE = 0x00;
    byte constant proofType_Ledger = 0x30;
    byte constant proofType_Native = 0xF0;
    byte constant proofStorage_IPFS = 0x01;
    byte constant proofType_Android = 0x40;
    byte constant proofType_TLSNotary = 0x10;

    string oraclize_network_name;
    uint8 constant networkID_auto = 0;
    uint8 constant networkID_morden = 2;
    uint8 constant networkID_mainnet = 1;
    uint8 constant networkID_testnet = 2;
    uint8 constant networkID_consensys = 161;

    mapping(bytes32 => bytes32) oraclize_randomDS_args;
    mapping(bytes32 => bool) oraclize_randomDS_sessionKeysHashVerified;

    modifier oraclizeAPI {
        if ((address(OAR) == address(0)) || (getCodeSize(address(OAR)) == 0)) {
            oraclize_setNetwork(networkID_auto);
        }
        if (address(oraclize) != OAR.getAddress()) {
            oraclize = OraclizeI(OAR.getAddress());
        }
        _;
    }

    modifier oraclize_randomDS_proofVerify(bytes32 _queryId, string memory _result, bytes memory _proof) {
        // RandomDS Proof Step 1: The prefix has to match 'LP\x01' (Ledger Proof version 1)
        require((_proof[0] == "L") && (_proof[1] == "P") && (uint8(_proof[2]) == uint8(1)));
        bool proofVerified = oraclize_randomDS_proofVerify__main(_proof, _queryId, bytes(_result), oraclize_getNetworkName());
        require(proofVerified);
        _;
    }

    function oraclize_setNetwork(uint8 _networkID) internal returns (bool _networkSet) {
      _networkID; // NOTE: Silence the warning and remain backwards compatible
      return oraclize_setNetwork();
    }

    function oraclize_setNetworkName(string memory _network_name) internal {
        oraclize_network_name = _network_name;
    }

    function oraclize_getNetworkName() internal view returns (string memory _networkName) {
        return oraclize_network_name;
    }

    function oraclize_setNetwork() internal returns (bool _networkSet) {
        if (getCodeSize(0x1d3B2638a7cC9f2CB3D298A3DA7a90B67E5506ed) > 0) { //mainnet
            OAR = OraclizeAddrResolverI(0x1d3B2638a7cC9f2CB3D298A3DA7a90B67E5506ed);
            oraclize_setNetworkName("eth_mainnet");
            return true;
        }
        if (getCodeSize(0xc03A2615D5efaf5F49F60B7BB6583eaec212fdf1) > 0) { //ropsten testnet
            OAR = OraclizeAddrResolverI(0xc03A2615D5efaf5F49F60B7BB6583eaec212fdf1);
            oraclize_setNetworkName("eth_ropsten3");
            return true;
        }
        if (getCodeSize(0xB7A07BcF2Ba2f2703b24C0691b5278999C59AC7e) > 0) { //kovan testnet
            OAR = OraclizeAddrResolverI(0xB7A07BcF2Ba2f2703b24C0691b5278999C59AC7e);
            oraclize_setNetworkName("eth_kovan");
            return true;
        }
        if (getCodeSize(0x146500cfd35B22E4A392Fe0aDc06De1a1368Ed48) > 0) { //rinkeby testnet
            OAR = OraclizeAddrResolverI(0x146500cfd35B22E4A392Fe0aDc06De1a1368Ed48);
            oraclize_setNetworkName("eth_rinkeby");
            return true;
        }
        if (getCodeSize(0xa2998EFD205FB9D4B4963aFb70778D6354ad3A41) > 0) { //goerli testnet
            OAR = OraclizeAddrResolverI(0xa2998EFD205FB9D4B4963aFb70778D6354ad3A41);
            oraclize_setNetworkName("eth_goerli");
            return true;
        }
        if (getCodeSize(0x6f485C8BF6fc43eA212E93BBF8ce046C7f1cb475) > 0) { //ethereum-bridge
            OAR = OraclizeAddrResolverI(0x6f485C8BF6fc43eA212E93BBF8ce046C7f1cb475);
            return true;
        }
        if (getCodeSize(0x20e12A1F859B3FeaE5Fb2A0A32C18F5a65555bBF) > 0) { //ether.camp ide
            OAR = OraclizeAddrResolverI(0x20e12A1F859B3FeaE5Fb2A0A32C18F5a65555bBF);
            return true;
        }
        if (getCodeSize(0x51efaF4c8B3C9AfBD5aB9F4bbC82784Ab6ef8fAA) > 0) { //browser-solidity
            OAR = OraclizeAddrResolverI(0x51efaF4c8B3C9AfBD5aB9F4bbC82784Ab6ef8fAA);
            return true;
        }
        return false;
    }
    /**
     * @dev The following `__callback` functions are just placeholders ideally
     *      meant to be defined in child contract when proofs are used.
     *      The function bodies simply silence compiler warnings.
     */
    function __callback(bytes32 _myid, string memory _result) public {
        __callback(_myid, _result, new bytes(0));
    }

    function __callback(bytes32 _myid, string memory _result, bytes memory _proof) public {
      _myid; _result; _proof;
      oraclize_randomDS_args[bytes32(0)] = bytes32(0);
    }

    function oraclize_getPrice(string memory _datasource) oraclizeAPI internal returns (uint _queryPrice) {
        return oraclize.getPrice(_datasource);
    }

    function oraclize_getPrice(string memory _datasource, uint _gasLimit) oraclizeAPI internal returns (uint _queryPrice) {
        return oraclize.getPrice(_datasource, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string memory _arg) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource);
        if (price > 1 ether + tx.gasprice * 200000) {
            return 0; // Unexpectedly high price
        }
        return oraclize.query.value(price)(0, _datasource, _arg);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string memory _arg) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource);
        if (price > 1 ether + tx.gasprice * 200000) {
            return 0; // Unexpectedly high price
        }
        return oraclize.query.value(price)(_timestamp, _datasource, _arg);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string memory _arg, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource,_gasLimit);
        if (price > 1 ether + tx.gasprice * _gasLimit) {
            return 0; // Unexpectedly high price
        }
        return oraclize.query_withGasLimit.value(price)(_timestamp, _datasource, _arg, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string memory _arg, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource, _gasLimit);
        if (price > 1 ether + tx.gasprice * _gasLimit) {
           return 0; // Unexpectedly high price
        }
        return oraclize.query_withGasLimit.value(price)(0, _datasource, _arg, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string memory _arg1, string memory _arg2) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource);
        if (price > 1 ether + tx.gasprice * 200000) {
            return 0; // Unexpectedly high price
        }
        return oraclize.query2.value(price)(0, _datasource, _arg1, _arg2);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string memory _arg1, string memory _arg2) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource);
        if (price > 1 ether + tx.gasprice * 200000) {
            return 0; // Unexpectedly high price
        }
        return oraclize.query2.value(price)(_timestamp, _datasource, _arg1, _arg2);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string memory _arg1, string memory _arg2, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource, _gasLimit);
        if (price > 1 ether + tx.gasprice * _gasLimit) {
            return 0; // Unexpectedly high price
        }
        return oraclize.query2_withGasLimit.value(price)(_timestamp, _datasource, _arg1, _arg2, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string memory _arg1, string memory _arg2, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource, _gasLimit);
        if (price > 1 ether + tx.gasprice * _gasLimit) {
            return 0; // Unexpectedly high price
        }
        return oraclize.query2_withGasLimit.value(price)(0, _datasource, _arg1, _arg2, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[] memory _argN) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource);
        if (price > 1 ether + tx.gasprice * 200000) {
            return 0; // Unexpectedly high price
        }
        bytes memory args = stra2cbor(_argN);
        return oraclize.queryN.value(price)(0, _datasource, args);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[] memory _argN) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource);
        if (price > 1 ether + tx.gasprice * 200000) {
            return 0; // Unexpectedly high price
        }
        bytes memory args = stra2cbor(_argN);
        return oraclize.queryN.value(price)(_timestamp, _datasource, args);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[] memory _argN, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource, _gasLimit);
        if (price > 1 ether + tx.gasprice * _gasLimit) {
            return 0; // Unexpectedly high price
        }
        bytes memory args = stra2cbor(_argN);
        return oraclize.queryN_withGasLimit.value(price)(_timestamp, _datasource, args, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[] memory _argN, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource, _gasLimit);
        if (price > 1 ether + tx.gasprice * _gasLimit) {
            return 0; // Unexpectedly high price
        }
        bytes memory args = stra2cbor(_argN);
        return oraclize.queryN_withGasLimit.value(price)(0, _datasource, args, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[1] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](1);
        dynargs[0] = _args[0];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[1] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](1);
        dynargs[0] = _args[0];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[1] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](1);
        dynargs[0] = _args[0];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[1] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](1);
        dynargs[0] = _args[0];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[2] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](2);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[2] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](2);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[2] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](2);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[2] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](2);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[3] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](3);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[3] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](3);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[3] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](3);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[3] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](3);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[4] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](4);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[4] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](4);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[4] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](4);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[4] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](4);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[5] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](5);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        dynargs[4] = _args[4];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[5] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](5);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        dynargs[4] = _args[4];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, string[5] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](5);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        dynargs[4] = _args[4];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, string[5] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        string[] memory dynargs = new string[](5);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        dynargs[4] = _args[4];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[] memory _argN) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource);
        if (price > 1 ether + tx.gasprice * 200000) {
            return 0; // Unexpectedly high price
        }
        bytes memory args = ba2cbor(_argN);
        return oraclize.queryN.value(price)(0, _datasource, args);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[] memory _argN) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource);
        if (price > 1 ether + tx.gasprice * 200000) {
            return 0; // Unexpectedly high price
        }
        bytes memory args = ba2cbor(_argN);
        return oraclize.queryN.value(price)(_timestamp, _datasource, args);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[] memory _argN, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource, _gasLimit);
        if (price > 1 ether + tx.gasprice * _gasLimit) {
            return 0; // Unexpectedly high price
        }
        bytes memory args = ba2cbor(_argN);
        return oraclize.queryN_withGasLimit.value(price)(_timestamp, _datasource, args, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[] memory _argN, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        uint price = oraclize.getPrice(_datasource, _gasLimit);
        if (price > 1 ether + tx.gasprice * _gasLimit) {
            return 0; // Unexpectedly high price
        }
        bytes memory args = ba2cbor(_argN);
        return oraclize.queryN_withGasLimit.value(price)(0, _datasource, args, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[1] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](1);
        dynargs[0] = _args[0];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[1] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](1);
        dynargs[0] = _args[0];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[1] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](1);
        dynargs[0] = _args[0];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[1] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](1);
        dynargs[0] = _args[0];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[2] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](2);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[2] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](2);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[2] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](2);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[2] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](2);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[3] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](3);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[3] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](3);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[3] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](3);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[3] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](3);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[4] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](4);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[4] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](4);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[4] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](4);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[4] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](4);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[5] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](5);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        dynargs[4] = _args[4];
        return oraclize_query(_datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[5] memory _args) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](5);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        dynargs[4] = _args[4];
        return oraclize_query(_timestamp, _datasource, dynargs);
    }

    function oraclize_query(uint _timestamp, string memory _datasource, bytes[5] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](5);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        dynargs[4] = _args[4];
        return oraclize_query(_timestamp, _datasource, dynargs, _gasLimit);
    }

    function oraclize_query(string memory _datasource, bytes[5] memory _args, uint _gasLimit) oraclizeAPI internal returns (bytes32 _id) {
        bytes[] memory dynargs = new bytes[](5);
        dynargs[0] = _args[0];
        dynargs[1] = _args[1];
        dynargs[2] = _args[2];
        dynargs[3] = _args[3];
        dynargs[4] = _args[4];
        return oraclize_query(_datasource, dynargs, _gasLimit);
    }

    function oraclize_setProof(byte _proofP) oraclizeAPI internal {
        return oraclize.setProofType(_proofP);
    }


    function oraclize_cbAddress() oraclizeAPI internal returns (address _callbackAddress) {
        return oraclize.cbAddress();
    }

    function getCodeSize(address _addr) view internal returns (uint _size) {
        assembly {
            _size := extcodesize(_addr)
        }
    }

    function oraclize_setCustomGasPrice(uint _gasPrice) oraclizeAPI internal {
        return oraclize.setCustomGasPrice(_gasPrice);
    }

    function oraclize_randomDS_getSessionPubKeyHash() oraclizeAPI internal returns (bytes32 _sessionKeyHash) {
        return oraclize.randomDS_getSessionPubKeyHash();
    }

    function parseAddr(string memory _a) internal pure returns (address _parsedAddress) {
        bytes memory tmp = bytes(_a);
        uint160 iaddr = 0;
        uint160 b1;
        uint160 b2;
        for (uint i = 2; i < 2 + 2 * 20; i += 2) {
            iaddr *= 256;
            b1 = uint160(uint8(tmp[i]));
            b2 = uint160(uint8(tmp[i + 1]));
            if ((b1 >= 97) && (b1 <= 102)) {
                b1 -= 87;
            } else if ((b1 >= 65) && (b1 <= 70)) {
                b1 -= 55;
            } else if ((b1 >= 48) && (b1 <= 57)) {
                b1 -= 48;
            }
            if ((b2 >= 97) && (b2 <= 102)) {
                b2 -= 87;
            } else if ((b2 >= 65) && (b2 <= 70)) {
                b2 -= 55;
            } else if ((b2 >= 48) && (b2 <= 57)) {
                b2 -= 48;
            }
            iaddr += (b1 * 16 + b2);
        }
        return address(iaddr);
    }

    function strCompare(string memory _a, string memory _b) internal pure returns (int _returnCode) {
        bytes memory a = bytes(_a);
        bytes memory b = bytes(_b);
        uint minLength = a.length;
        if (b.length < minLength) {
            minLength = b.length;
        }
        for (uint i = 0; i < minLength; i ++) {
            if (a[i] < b[i]) {
                return -1;
            } else if (a[i] > b[i]) {
                return 1;
            }
        }
        if (a.length < b.length) {
            return -1;
        } else if (a.length > b.length) {
            return 1;
        } else {
            return 0;
        }
    }

    function indexOf(string memory _haystack, string memory _needle) internal pure returns (int _returnCode) {
        bytes memory h = bytes(_haystack);
        bytes memory n = bytes(_needle);
        if (h.length < 1 || n.length < 1 || (n.length > h.length)) {
            return -1;
        } else if (h.length > (2 ** 128 - 1)) {
            return -1;
        } else {
            uint subindex = 0;
            for (uint i = 0; i < h.length; i++) {
                if (h[i] == n[0]) {
                    subindex = 1;
                    while(subindex < n.length && (i + subindex) < h.length && h[i + subindex] == n[subindex]) {
                        subindex++;
                    }
                    if (subindex == n.length) {
                        return int(i);
                    }
                }
            }
            return -1;
        }
    }

    function strConcat(string memory _a, string memory _b) internal pure returns (string memory _concatenatedString) {
        return strConcat(_a, _b, "", "", "");
    }

    function strConcat(string memory _a, string memory _b, string memory _c) internal pure returns (string memory _concatenatedString) {
        return strConcat(_a, _b, _c, "", "");
    }

    function strConcat(string memory _a, string memory _b, string memory _c, string memory _d) internal pure returns (string memory _concatenatedString) {
        return strConcat(_a, _b, _c, _d, "");
    }

    function strConcat(string memory _a, string memory _b, string memory _c, string memory _d, string memory _e) internal pure returns (string memory _concatenatedString) {
        bytes memory _ba = bytes(_a);
        bytes memory _bb = bytes(_b);
        bytes memory _bc = bytes(_c);
        bytes memory _bd = bytes(_d);
        bytes memory _be = bytes(_e);
        string memory abcde = new string(_ba.length + _bb.length + _bc.length + _bd.length + _be.length);
        bytes memory babcde = bytes(abcde);
        uint k = 0;
        uint i = 0;
        for (i = 0; i < _ba.length; i++) {
            babcde[k++] = _ba[i];
        }
        for (i = 0; i < _bb.length; i++) {
            babcde[k++] = _bb[i];
        }
        for (i = 0; i < _bc.length; i++) {
            babcde[k++] = _bc[i];
        }
        for (i = 0; i < _bd.length; i++) {
            babcde[k++] = _bd[i];
        }
        for (i = 0; i < _be.length; i++) {
            babcde[k++] = _be[i];
        }
        return string(babcde);
    }

    function safeParseInt(string memory _a) internal pure returns (uint _parsedInt) {
        return safeParseInt(_a, 0);
    }

    function safeParseInt(string memory _a, uint _b) internal pure returns (uint _parsedInt) {
        bytes memory bresult = bytes(_a);
        uint mint = 0;
        bool decimals = false;
        for (uint i = 0; i < bresult.length; i++) {
            if ((uint(uint8(bresult[i])) >= 48) && (uint(uint8(bresult[i])) <= 57)) {
                if (decimals) {
                   if (_b == 0) break;
                    else _b--;
                }
                mint *= 10;
                mint += uint(uint8(bresult[i])) - 48;
            } else if (uint(uint8(bresult[i])) == 46) {
                require(!decimals, 'More than one decimal encountered in string!');
                decimals = true;
            } else {
                revert("Non-numeral character encountered in string!");
            }
        }
        if (_b > 0) {
            mint *= 10 ** _b;
        }
        return mint;
    }

    function parseInt(string memory _a) internal pure returns (uint _parsedInt) {
        return parseInt(_a, 0);
    }

    function parseInt(string memory _a, uint _b) internal pure returns (uint _parsedInt) {
        bytes memory bresult = bytes(_a);
        uint mint = 0;
        bool decimals = false;
        for (uint i = 0; i < bresult.length; i++) {
            if ((uint(uint8(bresult[i])) >= 48) && (uint(uint8(bresult[i])) <= 57)) {
                if (decimals) {
                   if (_b == 0) {
                       break;
                   } else {
                       _b--;
                   }
                }
                mint *= 10;
                mint += uint(uint8(bresult[i])) - 48;
            } else if (uint(uint8(bresult[i])) == 46) {
                decimals = true;
            }
        }
        if (_b > 0) {
            mint *= 10 ** _b;
        }
        return mint;
    }

    function uint2str(uint _i) internal pure returns (string memory _uintAsString) {
        if (_i == 0) {
            return "0";
        }
        uint j = _i;
        uint len;
        while (j != 0) {
            len++;
            j /= 10;
        }
        bytes memory bstr = new bytes(len);
        uint k = len - 1;
        while (_i != 0) {
            bstr[k--] = byte(uint8(48 + _i % 10));
            _i /= 10;
        }
        return string(bstr);
    }

    function stra2cbor(string[] memory _arr) internal pure returns (bytes memory _cborEncoding) {
        safeMemoryCleaner();
        OraclizeBuffer.buffer memory buf;
        OraclizeBuffer.init(buf, 1024);
        buf.startArray();
        for (uint i = 0; i < _arr.length; i++) {
            buf.encodeString(_arr[i]);
        }
        buf.endSequence();
        return buf.buf;
    }

    function ba2cbor(bytes[] memory _arr) internal pure returns (bytes memory _cborEncoding) {
        safeMemoryCleaner();
        OraclizeBuffer.buffer memory buf;
        OraclizeBuffer.init(buf, 1024);
        buf.startArray();
        for (uint i = 0; i < _arr.length; i++) {
            buf.encodeBytes(_arr[i]);
        }
        buf.endSequence();
        return buf.buf;
    }

    function oraclize_newRandomDSQuery(uint _delay, uint _nbytes, uint _customGasLimit) internal returns (bytes32 _queryId) {
        require((_nbytes > 0) && (_nbytes <= 32));
        _delay *= 10; // Convert from seconds to ledger timer ticks
        bytes memory nbytes = new bytes(1);
        nbytes[0] = byte(uint8(_nbytes));
        bytes memory unonce = new bytes(32);
        bytes memory sessionKeyHash = new bytes(32);
        bytes32 sessionKeyHash_bytes32 = oraclize_randomDS_getSessionPubKeyHash();
        assembly {
            mstore(unonce, 0x20)
            /*
             The following variables can be relaxed.
             Check the relaxed random contract at https://github.com/oraclize/ethereum-examples
             for an idea on how to override and replace commit hash variables.
            */
            mstore(add(unonce, 0x20), xor(blockhash(sub(number, 1)), xor(coinbase, timestamp)))
            mstore(sessionKeyHash, 0x20)
            mstore(add(sessionKeyHash, 0x20), sessionKeyHash_bytes32)
        }
        bytes memory delay = new bytes(32);
        assembly {
            mstore(add(delay, 0x20), _delay)
        }
        bytes memory delay_bytes8 = new bytes(8);
        copyBytes(delay, 24, 8, delay_bytes8, 0);
        bytes[4] memory args = [unonce, nbytes, sessionKeyHash, delay];
        bytes32 queryId = oraclize_query("random", args, _customGasLimit);
        bytes memory delay_bytes8_left = new bytes(8);
        assembly {
            let x := mload(add(delay_bytes8, 0x20))
            mstore8(add(delay_bytes8_left, 0x27), div(x, 0x100000000000000000000000000000000000000000000000000000000000000))
            mstore8(add(delay_bytes8_left, 0x26), div(x, 0x1000000000000000000000000000000000000000000000000000000000000))
            mstore8(add(delay_bytes8_left, 0x25), div(x, 0x10000000000000000000000000000000000000000000000000000000000))
            mstore8(add(delay_bytes8_left, 0x24), div(x, 0x100000000000000000000000000000000000000000000000000000000))
            mstore8(add(delay_bytes8_left, 0x23), div(x, 0x1000000000000000000000000000000000000000000000000000000))
            mstore8(add(delay_bytes8_left, 0x22), div(x, 0x10000000000000000000000000000000000000000000000000000))
            mstore8(add(delay_bytes8_left, 0x21), div(x, 0x100000000000000000000000000000000000000000000000000))
            mstore8(add(delay_bytes8_left, 0x20), div(x, 0x1000000000000000000000000000000000000000000000000))
        }
        oraclize_randomDS_setCommitment(queryId, keccak256(abi.encodePacked(delay_bytes8_left, args[1], sha256(args[0]), args[2])));
        return queryId;
    }

    function oraclize_randomDS_setCommitment(bytes32 _queryId, bytes32 _commitment) internal {
        oraclize_randomDS_args[_queryId] = _commitment;
    }

    function verifySig(bytes32 _tosignh, bytes memory _dersig, bytes memory _pubkey) internal returns (bool _sigVerified) {
        bool sigok;
        address signer;
        bytes32 sigr;
        bytes32 sigs;
        bytes memory sigr_ = new bytes(32);
        uint offset = 4 + (uint(uint8(_dersig[3])) - 0x20);
        sigr_ = copyBytes(_dersig, offset, 32, sigr_, 0);
        bytes memory sigs_ = new bytes(32);
        offset += 32 + 2;
        sigs_ = copyBytes(_dersig, offset + (uint(uint8(_dersig[offset - 1])) - 0x20), 32, sigs_, 0);
        assembly {
            sigr := mload(add(sigr_, 32))
            sigs := mload(add(sigs_, 32))
        }
        (sigok, signer) = safer_ecrecover(_tosignh, 27, sigr, sigs);
        if (address(uint160(uint256(keccak256(_pubkey)))) == signer) {
            return true;
        } else {
            (sigok, signer) = safer_ecrecover(_tosignh, 28, sigr, sigs);
            return (address(uint160(uint256(keccak256(_pubkey)))) == signer);
        }
    }

    function oraclize_randomDS_proofVerify__sessionKeyValidity(bytes memory _proof, uint _sig2offset) internal returns (bool _proofVerified) {
        bool sigok;
        // Random DS Proof Step 6: Verify the attestation signature, APPKEY1 must sign the sessionKey from the correct ledger app (CODEHASH)
        bytes memory sig2 = new bytes(uint(uint8(_proof[_sig2offset + 1])) + 2);
        copyBytes(_proof, _sig2offset, sig2.length, sig2, 0);
        bytes memory appkey1_pubkey = new bytes(64);
        copyBytes(_proof, 3 + 1, 64, appkey1_pubkey, 0);
        bytes memory tosign2 = new bytes(1 + 65 + 32);
        tosign2[0] = byte(uint8(1)); //role
        copyBytes(_proof, _sig2offset - 65, 65, tosign2, 1);
        bytes memory CODEHASH = hex"fd94fa71bc0ba10d39d464d0d8f465efeef0a2764e3887fcc9df41ded20f505c";
        copyBytes(CODEHASH, 0, 32, tosign2, 1 + 65);
        sigok = verifySig(sha256(tosign2), sig2, appkey1_pubkey);
        if (!sigok) {
            return false;
        }
        // Random DS Proof Step 7: Verify the APPKEY1 provenance (must be signed by Ledger)
        bytes memory LEDGERKEY = hex"7fb956469c5c9b89840d55b43537e66a98dd4811ea0a27224272c2e5622911e8537a2f8e86a46baec82864e98dd01e9ccc2f8bc5dfc9cbe5a91a290498dd96e4";
        bytes memory tosign3 = new bytes(1 + 65);
        tosign3[0] = 0xFE;
        copyBytes(_proof, 3, 65, tosign3, 1);
        bytes memory sig3 = new bytes(uint(uint8(_proof[3 + 65 + 1])) + 2);
        copyBytes(_proof, 3 + 65, sig3.length, sig3, 0);
        sigok = verifySig(sha256(tosign3), sig3, LEDGERKEY);
        return sigok;
    }

    function oraclize_randomDS_proofVerify__returnCode(bytes32 _queryId, string memory _result, bytes memory _proof) internal returns (uint8 _returnCode) {
        // Random DS Proof Step 1: The prefix has to match 'LP\x01' (Ledger Proof version 1)
        if ((_proof[0] != "L") || (_proof[1] != "P") || (uint8(_proof[2]) != uint8(1))) {
            return 1;
        }
        bool proofVerified = oraclize_randomDS_proofVerify__main(_proof, _queryId, bytes(_result), oraclize_getNetworkName());
        if (!proofVerified) {
            return 2;
        }
        return 0;
    }

    function matchBytes32Prefix(bytes32 _content, bytes memory _prefix, uint _nRandomBytes) internal pure returns (bool _matchesPrefix) {
        bool match_ = true;
        require(_prefix.length == _nRandomBytes);
        for (uint256 i = 0; i< _nRandomBytes; i++) {
            if (_content[i] != _prefix[i]) {
                match_ = false;
            }
        }
        return match_;
    }

    function oraclize_randomDS_proofVerify__main(bytes memory _proof, bytes32 _queryId, bytes memory _result, string memory _contextName) internal returns (bool _proofVerified) {
        // Random DS Proof Step 2: The unique keyhash has to match with the sha256 of (context name + _queryId)
        uint ledgerProofLength = 3 + 65 + (uint(uint8(_proof[3 + 65 + 1])) + 2) + 32;
        bytes memory keyhash = new bytes(32);
        copyBytes(_proof, ledgerProofLength, 32, keyhash, 0);
        if (!(keccak256(keyhash) == keccak256(abi.encodePacked(sha256(abi.encodePacked(_contextName, _queryId)))))) {
            return false;
        }
        bytes memory sig1 = new bytes(uint(uint8(_proof[ledgerProofLength + (32 + 8 + 1 + 32) + 1])) + 2);
        copyBytes(_proof, ledgerProofLength + (32 + 8 + 1 + 32), sig1.length, sig1, 0);
        // Random DS Proof Step 3: We assume sig1 is valid (it will be verified during step 5) and we verify if '_result' is the _prefix of sha256(sig1)
        if (!matchBytes32Prefix(sha256(sig1), _result, uint(uint8(_proof[ledgerProofLength + 32 + 8])))) {
            return false;
        }
        // Random DS Proof Step 4: Commitment match verification, keccak256(delay, nbytes, unonce, sessionKeyHash) == commitment in storage.
        // This is to verify that the computed args match with the ones specified in the query.
        bytes memory commitmentSlice1 = new bytes(8 + 1 + 32);
        copyBytes(_proof, ledgerProofLength + 32, 8 + 1 + 32, commitmentSlice1, 0);
        bytes memory sessionPubkey = new bytes(64);
        uint sig2offset = ledgerProofLength + 32 + (8 + 1 + 32) + sig1.length + 65;
        copyBytes(_proof, sig2offset - 64, 64, sessionPubkey, 0);
        bytes32 sessionPubkeyHash = sha256(sessionPubkey);
        if (oraclize_randomDS_args[_queryId] == keccak256(abi.encodePacked(commitmentSlice1, sessionPubkeyHash))) { //unonce, nbytes and sessionKeyHash match
            delete oraclize_randomDS_args[_queryId];
        } else return false;
        // Random DS Proof Step 5: Validity verification for sig1 (keyhash and args signed with the sessionKey)
        bytes memory tosign1 = new bytes(32 + 8 + 1 + 32);
        copyBytes(_proof, ledgerProofLength, 32 + 8 + 1 + 32, tosign1, 0);
        if (!verifySig(sha256(tosign1), sig1, sessionPubkey)) {
            return false;
        }
        // Verify if sessionPubkeyHash was verified already, if not.. let's do it!
        if (!oraclize_randomDS_sessionKeysHashVerified[sessionPubkeyHash]) {
            oraclize_randomDS_sessionKeysHashVerified[sessionPubkeyHash] = oraclize_randomDS_proofVerify__sessionKeyValidity(_proof, sig2offset);
        }
        return oraclize_randomDS_sessionKeysHashVerified[sessionPubkeyHash];
    }
    /*
     The following function has been written by Alex Beregszaszi, use it under the terms of the MIT license
    */
    function copyBytes(bytes memory _from, uint _fromOffset, uint _length, bytes memory _to, uint _toOffset) internal pure returns (bytes memory _copiedBytes) {
        uint minLength = _length + _toOffset;
        require(_to.length >= minLength); // Buffer too small. Should be a better way?
        uint i = 32 + _fromOffset; // NOTE: the offset 32 is added to skip the `size` field of both bytes variables
        uint j = 32 + _toOffset;
        while (i < (32 + _fromOffset + _length)) {
            assembly {
                let tmp := mload(add(_from, i))
                mstore(add(_to, j), tmp)
            }
            i += 32;
            j += 32;
        }
        return _to;
    }
    /*
     The following function has been written by Alex Beregszaszi, use it under the terms of the MIT license
     Duplicate Solidity's ecrecover, but catching the CALL return value
    */
    function safer_ecrecover(bytes32 _hash, uint8 _v, bytes32 _r, bytes32 _s) internal returns (bool _success, address _recoveredAddress) {
        /*
         We do our own memory management here. Solidity uses memory offset
         0x40 to store the current end of memory. We write past it (as
         writes are memory extensions), but don't update the offset so
         Solidity will reuse it. The memory used here is only needed for
         this context.
         FIXME: inline assembly can't access return values
        */
        bool ret;
        address addr;
        assembly {
            let size := mload(0x40)
            mstore(size, _hash)
            mstore(add(size, 32), _v)
            mstore(add(size, 64), _r)
            mstore(add(size, 96), _s)
            ret := call(3000, 1, 0, size, 128, size, 32) // NOTE: we can reuse the request memory because we deal with the return code.
            addr := mload(size)
        }
        return (ret, addr);
    }
    /*
     The following function has been written by Alex Beregszaszi, use it under the terms of the MIT license
    */
    function ecrecovery(bytes32 _hash, bytes memory _sig) internal returns (bool _success, address _recoveredAddress) {
        bytes32 r;
        bytes32 s;
        uint8 v;
        if (_sig.length != 65) {
            return (false, address(0));
        }
        /*
         The signature format is a compact form of:
           {bytes32 r}{bytes32 s}{uint8 v}
         Compact means, uint8 is not padded to 32 bytes.
        */
        assembly {
            r := mload(add(_sig, 32))
            s := mload(add(_sig, 64))
            /*
             Here we are loading the last 32 bytes. We exploit the fact that
             'mload' will pad with zeroes if we overread.
             There is no 'mload8' to do this, but that would be nicer.
            */
            v := byte(0, mload(add(_sig, 96)))
            /*
              Alternative solution:
              'byte' is not working due to the Solidity parser, so lets
              use the second best option, 'and'
              v := and(mload(add(_sig, 65)), 255)
            */
        }
        /*
         albeit non-transactional signatures are not specified by the YP, one would expect it
         to match the YP range of [27, 28]
         geth uses [0, 1] and some clients have followed. This might change, see:
         https://github.com/ethereum/go-ethereum/issues/2053
        */
        if (v < 27) {
            v += 27;
        }
        if (v != 27 && v != 28) {
            return (false, address(0));
        }
        return safer_ecrecover(_hash, v, r, s);
    }

    function safeMemoryCleaner() internal pure {
        assembly {
            let fmem := mload(0x40)
            codecopy(fmem, codesize, sub(msize, fmem))
        }
    }
}

/*

END ORACLIZE_API

*/

// SPDX-License-Identifier: MIT
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// SPDX-License-Identifier: MIT
contract PoliToken {
	// Conditioners
	using SafeMath for uint;


	// Storage
	string public name = "CoolToken";
	string public symbol = "COOL";
	string	public standard = "CoolToken v1.0";
	uint public totalSupply; // number of tokens
	mapping(address => uint) public balanceOf; // _owner => _balance
	mapping(address => mapping(address => uint)) public allowance; // _owner => [_spender => _value]

	address[] private holderList; // enables accessing poliHolder balances, by iterating over this list of poliHolders.
	mapping(address => uint) public holderPointers; // poliHolderAddrs => listPointers
	// https://ethereum.stackexchange.com/questions/13167/are-there-well-solved-and-simple-storage-patterns-for-solidity


	// ERC20 Events
	event Transfer(
		address indexed _from,
		address indexed _to,
		uint _value
	);

	event Approval(
		address indexed _owner,
		address indexed _spender,
		uint _value
	);


	// Constructor
	constructor(uint _initialSupply) public {
		totalSupply = _initialSupply;
		balanceOf[msg.sender] = _initialSupply; // all tokens initially go to the creator of the poli
	}


	// ERC20 Transfer
	function transfer(address _to, uint _value) public returns (bool success) {
		// trigger exception if the sender doesn't have enough
		require(balanceOf[msg.sender] >= _value);

		// change balances
		balanceOf[msg.sender] -= _value;
		balanceOf[_to] += _value;

		// announce
		emit Transfer(msg.sender, _to, _value);

		// update current holder data
		updateTransactionHolders(msg.sender, _to);

		return true;
	}


	// ERC-20 Delegated Transfer
	function approve(address _spender, uint _value) public returns (bool success) {
		allowance[msg.sender][_spender] = _value;
		emit Approval(msg.sender, _spender, _value);
		return true;
	}

	function transferFrom(address _from, address _to, uint _value) public returns (bool success) {
		// require that _from has enough tokens and allowance is big enough
		require(_value <= balanceOf[_from]);
		require(_value <= allowance[_from][msg.sender]);

		// change the balance and update the allowance
		balanceOf[_from] -= _value;
		balanceOf[_to] += _value;
		allowance[_from][msg.sender] -= _value;

		// announce
		emit Transfer(_from, _to, _value);

		// update current holder data
		updateTransactionHolders(_from, _to);

		return true;
	}


	// Holder Helpers
  	function isHolder(address _holderAddress) public view returns(bool isIndeed) {
    	if(holderList.length == 0) return false;
    	return (holderList[holderPointers[_holderAddress]] == _holderAddress);
  	}

  	function getHolderCount() public view returns(uint holderCount) {
    	return holderList.length;
  	}

  	function newHolder(address _holderAddress) private returns(bool success) {
    	require(!isHolder(_holderAddress));
    	holderPointers[_holderAddress] = holderList.push(_holderAddress).sub(1);
    	return true;
  	}

  	function deleteHolder(address _holderAddress) private returns(bool success) {
    	require(isHolder(_holderAddress));
    	uint rowToDelete = holderPointers[_holderAddress];
    	address keyToMove   = holderList[holderList.length.sub(1)];
    	holderList[rowToDelete] = keyToMove;
    	holderPointers[keyToMove] = rowToDelete;
    	holderList.length.sub(1);
    	return true;
  	}

  	function updateTransactionHolders(address _sender, address _receiver) private returns(bool success) {
  		if (balanceOf[_sender] == 0) deleteHolder(_sender); // deleteHolder _sender if _sender now has a 0 balance
		if (!isHolder(_receiver)) newHolder(_receiver); // make _receiver a newHolder, if not already
		return true;
  	}

}

/**
 * @title FixidityLib
 * @author Gadi Guy, Alberto Cuesta Canada
 * @notice This library provides fixed point arithmetic with protection against
 * overflow. 
 * All operations are done with int256 and the operands must have been created 
 * with any of the newFrom* functions, which shift the comma digits() to the 
 * right and check for limits.
 * When using this library be sure of using maxNewFixed() as the upper limit for
 * creation of fixed point numbers. Use maxFixedMul(), maxFixedDiv() and
 * maxFixedAdd() if you want to be certain that those operations don't 
 * overflow.
 */
library FixidityLib {

    /**
     * @notice Number of positions that the comma is shifted to the right.
     */
    function digits() public pure returns(uint8) {
        return 24;
    }
    
    /**
     * @notice This is 1 in the fixed point units used in this library.
     * @dev Test fixed1() equals 10^digits()
     * Hardcoded to 24 digits.
     */
    function fixed1() public pure returns(int256) {
        return 1000000000000000000000000;
    }

    /**
     * @notice The amount of decimals lost on each multiplication operand.
     * @dev Test mulPrecision() equals sqrt(fixed1)
     * Hardcoded to 24 digits.
     */
    function mulPrecision() public pure returns(int256) {
        return 1000000000000;
    }

    /**
     * @notice Maximum value that can be represented in an int256
     * @dev Test maxInt256() equals 2^255 -1
     */
    function maxInt256() public pure returns(int256) {
        return 57896044618658097711785492504343953926634992332820282019728792003956564819967;
    }

    /**
     * @notice Minimum value that can be represented in an int256
     * @dev Test minInt256 equals (2^255) * (-1)
     */
    function minInt256() public pure returns(int256) {
        return -57896044618658097711785492504343953926634992332820282019728792003956564819968;
    }

    /**
     * @notice Maximum value that can be converted to fixed point. Optimize for
     * @dev deployment. 
     * Test maxNewFixed() equals maxInt256() / fixed1()
     * Hardcoded to 24 digits.
     */
    function maxNewFixed() public pure returns(int256) {
        return 57896044618658097711785492504343953926634992332820282;
    }

    /**
     * @notice Maximum value that can be converted to fixed point. Optimize for
     * deployment. 
     * @dev Test minNewFixed() equals -(maxInt256()) / fixed1()
     * Hardcoded to 24 digits.
     */
    function minNewFixed() public pure returns(int256) {
        return -57896044618658097711785492504343953926634992332820282;
    }

    /**
     * @notice Maximum value that can be safely used as an addition operator.
     * @dev Test maxFixedAdd() equals maxInt256()-1 / 2
     * Test add(maxFixedAdd(),maxFixedAdd()) equals maxFixedAdd() + maxFixedAdd()
     * Test add(maxFixedAdd()+1,maxFixedAdd()) throws 
     * Test add(-maxFixedAdd(),-maxFixedAdd()) equals -maxFixedAdd() - maxFixedAdd()
     * Test add(-maxFixedAdd(),-maxFixedAdd()-1) throws 
     */
    function maxFixedAdd() public pure returns(int256) {
        return 28948022309329048855892746252171976963317496166410141009864396001978282409983;
    }

    /**
     * @notice Maximum negative value that can be safely in a subtraction.
     * @dev Test maxFixedSub() equals minInt256() / 2
     */
    function maxFixedSub() public pure returns(int256) {
        return -28948022309329048855892746252171976963317496166410141009864396001978282409984;
    }

    /**
     * @notice Maximum value that can be safely used as a multiplication operator.
     * @dev Calculated as sqrt(maxInt256()*fixed1()). 
     * Be careful with your sqrt() implementation. I couldn't find a calculator
     * that would give the exact square root of maxInt256*fixed1 so this number
     * is below the real number by no more than 3*10**28. It is safe to use as
     * a limit for your multiplications, although powers of two of numbers over
     * this value might still work.
     * Test multiply(maxFixedMul(),maxFixedMul()) equals maxFixedMul() * maxFixedMul()
     * Test multiply(maxFixedMul(),maxFixedMul()+1) throws 
     * Test multiply(-maxFixedMul(),maxFixedMul()) equals -maxFixedMul() * maxFixedMul()
     * Test multiply(-maxFixedMul(),maxFixedMul()+1) throws 
     * Hardcoded to 24 digits.
     */
    function maxFixedMul() public pure returns(int256) {
        return 240615969168004498257251713877715648331380787511296;
    }

    /**
     * @notice Maximum value that can be safely used as a dividend.
     * @dev divide(maxFixedDiv,newFixedFraction(1,fixed1())) = maxInt256().
     * Test maxFixedDiv() equals maxInt256()/fixed1()
     * Test divide(maxFixedDiv(),multiply(mulPrecision(),mulPrecision())) = maxFixedDiv()*(10^digits())
     * Test divide(maxFixedDiv()+1,multiply(mulPrecision(),mulPrecision())) throws
     * Hardcoded to 24 digits.
     */
    function maxFixedDiv() public pure returns(int256) {
        return 57896044618658097711785492504343953926634992332820282;
    }

    /**
     * @notice Maximum value that can be safely used as a divisor.
     * @dev Test maxFixedDivisor() equals fixed1()*fixed1() - Or 10**(digits()*2)
     * Test divide(10**(digits()*2 + 1),10**(digits()*2)) = returns 10*fixed1()
     * Test divide(10**(digits()*2 + 1),10**(digits()*2 + 1)) = throws
     * Hardcoded to 24 digits.
     */
    function maxFixedDivisor() public pure returns(int256) {
        return 1000000000000000000000000000000000000000000000000;
    }

    /**
     * @notice Converts an int256 to fixed point units, equivalent to multiplying
     * by 10^digits().
     * @dev Test newFixed(0) returns 0
     * Test newFixed(1) returns fixed1()
     * Test newFixed(maxNewFixed()) returns maxNewFixed() * fixed1()
     * Test newFixed(maxNewFixed()+1) fails
     */
    function newFixed(int256 x)
        public
        pure
        returns (int256)
    {
        assert(x <= maxNewFixed());
        assert(x >= minNewFixed());
        return x * fixed1();
    }

    /**
     * @notice Converts an int256 in the fixed point representation of this 
     * library to a non decimal. All decimal digits will be truncated.
     */
    function fromFixed(int256 x)
        public
        pure
        returns (int256)
    {
        return x / fixed1();
    }

    /**
     * @notice Converts an int256 which is already in some fixed point 
     * representation to a different fixed precision representation.
     * Both the origin and destination precisions must be 38 or less digits.
     * Origin values with a precision higher than the destination precision
     * will be truncated accordingly.
     * @dev 
     * Test convertFixed(1,0,0) returns 1;
     * Test convertFixed(1,1,1) returns 1;
     * Test convertFixed(1,1,0) returns 0;
     * Test convertFixed(1,0,1) returns 10;
     * Test convertFixed(10,1,0) returns 1;
     * Test convertFixed(10,0,1) returns 100;
     * Test convertFixed(100,1,0) returns 10;
     * Test convertFixed(100,0,1) returns 1000;
     * Test convertFixed(1000,2,0) returns 10;
     * Test convertFixed(1000,0,2) returns 100000;
     * Test convertFixed(1000,2,1) returns 100;
     * Test convertFixed(1000,1,2) returns 10000;
     * Test convertFixed(maxInt256,1,0) returns maxInt256/10;
     * Test convertFixed(maxInt256,0,1) throws
     * Test convertFixed(maxInt256,38,0) returns maxInt256/(10**38);
     * Test convertFixed(1,0,38) returns 10**38;
     * Test convertFixed(maxInt256,39,0) throws
     * Test convertFixed(1,0,39) throws
     */
    function convertFixed(int256 x, uint8 _originDigits, uint8 _destinationDigits)
        public
        pure
        returns (int256)
    {
        assert(_originDigits <= 38 && _destinationDigits <= 38);
        
        uint8 decimalDifference;
        if ( _originDigits > _destinationDigits ){
            decimalDifference = _originDigits - _destinationDigits;
            return x/(uint128(10)**uint128(decimalDifference));
        }
        else if ( _originDigits < _destinationDigits ){
            decimalDifference = _destinationDigits - _originDigits;
            // Cast uint8 -> uint128 is safe
            // Exponentiation is safe:
            //     _originDigits and _destinationDigits limited to 38 or less
            //     decimalDifference = abs(_destinationDigits - _originDigits)
            //     decimalDifference < 38
            //     10**38 < 2**128-1
            assert(x <= maxInt256()/uint128(10)**uint128(decimalDifference));
            assert(x >= minInt256()/uint128(10)**uint128(decimalDifference));
            return x*(uint128(10)**uint128(decimalDifference));
        }
        // _originDigits == digits()) 
        return x;
    }

    /**
     * @notice Converts an int256 which is already in some fixed point 
     * representation to that of this library. The _originDigits parameter is the
     * precision of x. Values with a precision higher than FixidityLib.digits()
     * will be truncated accordingly.
     */
    function newFixed(int256 x, uint8 _originDigits)
        public
        pure
        returns (int256)
    {
        return convertFixed(x, _originDigits, digits());
    }

    /**
     * @notice Converts an int256 in the fixed point representation of this 
     * library to a different representation. The _destinationDigits parameter is the
     * precision of the output x. Values with a precision below than 
     * FixidityLib.digits() will be truncated accordingly.
     */
    function fromFixed(int256 x, uint8 _destinationDigits)
        public
        pure
        returns (int256)
    {
        return convertFixed(x, digits(), _destinationDigits);
    }

    /**
     * @notice Converts two int256 representing a fraction to fixed point units,
     * equivalent to multiplying dividend and divisor by 10^digits().
     * @dev 
     * Test newFixedFraction(maxFixedDiv()+1,1) fails
     * Test newFixedFraction(1,maxFixedDiv()+1) fails
     * Test newFixedFraction(1,0) fails     
     * Test newFixedFraction(0,1) returns 0
     * Test newFixedFraction(1,1) returns fixed1()
     * Test newFixedFraction(maxFixedDiv(),1) returns maxFixedDiv()*fixed1()
     * Test newFixedFraction(1,fixed1()) returns 1
     * Test newFixedFraction(1,fixed1()-1) returns 0
     */
    function newFixedFraction(
        int256 numerator, 
        int256 denominator
        )
        public
        pure
        returns (int256)
    {
        assert(numerator <= maxNewFixed());
        assert(denominator <= maxNewFixed());
        assert(denominator != 0);
        int256 convertedNumerator = newFixed(numerator);
        int256 convertedDenominator = newFixed(denominator);
        return divide(convertedNumerator, convertedDenominator);
    }

    /**
     * @notice Returns the integer part of a fixed point number.
     * @dev 
     * Test integer(0) returns 0
     * Test integer(fixed1()) returns fixed1()
     * Test integer(newFixed(maxNewFixed())) returns maxNewFixed()*fixed1()
     * Test integer(-fixed1()) returns -fixed1()
     * Test integer(newFixed(-maxNewFixed())) returns -maxNewFixed()*fixed1()
     */
    function integer(int256 x) public pure returns (int256) {
        return (x / fixed1()) * fixed1(); // Can't overflow
    }

    /**
     * @notice Returns the fractional part of a fixed point number. 
     * In the case of a negative number the fractional is also negative.
     * @dev 
     * Test fractional(0) returns 0
     * Test fractional(fixed1()) returns 0
     * Test fractional(fixed1()-1) returns 10^24-1
     * Test fractional(-fixed1()) returns 0
     * Test fractional(-fixed1()+1) returns -10^24-1
     */
    function fractional(int256 x) public pure returns (int256) {
        return x - (x / fixed1()) * fixed1(); // Can't overflow
    }

    /**
     * @notice Converts to positive if negative.
     * Due to int256 having one more negative number than positive numbers 
     * abs(minInt256) reverts.
     * @dev 
     * Test abs(0) returns 0
     * Test abs(fixed1()) returns -fixed1()
     * Test abs(-fixed1()) returns fixed1()
     * Test abs(newFixed(maxNewFixed())) returns maxNewFixed()*fixed1()
     * Test abs(newFixed(minNewFixed())) returns -minNewFixed()*fixed1()
     */
    function abs(int256 x) public pure returns (int256) {
        if (x >= 0) {
            return x;
        } else {
            int256 result = -x;
            assert (result > 0);
            return result;
        }
    }

    /**
     * @notice x+y. If any operator is higher than maxFixedAdd() it 
     * might overflow.
     * In solidity maxInt256 + 1 = minInt256 and viceversa.
     * @dev 
     * Test add(maxFixedAdd(),maxFixedAdd()) returns maxInt256()-1
     * Test add(maxFixedAdd()+1,maxFixedAdd()+1) fails
     * Test add(-maxFixedSub(),-maxFixedSub()) returns minInt256()
     * Test add(-maxFixedSub()-1,-maxFixedSub()-1) fails
     * Test add(maxInt256(),maxInt256()) fails
     * Test add(minInt256(),minInt256()) fails
     */
    function add(int256 x, int256 y) public pure returns (int256) {
        int256 z = x + y;
        if (x > 0 && y > 0) assert(z > x && z > y);
        if (x < 0 && y < 0) assert(z < x && z < y);
        return z;
    }

    /**
     * @notice x-y. You can use add(x,-y) instead. 
     * @dev Tests covered by add(x,y)
     */
    function subtract(int256 x, int256 y) public pure returns (int256) {
        return add(x,-y);
    }

    /**
     * @notice x*y. If any of the operators is higher than maxFixedMul() it 
     * might overflow.
     * @dev 
     * Test multiply(0,0) returns 0
     * Test multiply(maxFixedMul(),0) returns 0
     * Test multiply(0,maxFixedMul()) returns 0
     * Test multiply(maxFixedMul(),fixed1()) returns maxFixedMul()
     * Test multiply(fixed1(),maxFixedMul()) returns maxFixedMul()
     * Test all combinations of (2,-2), (2, 2.5), (2, -2.5) and (0.5, -0.5)
     * Test multiply(fixed1()/mulPrecision(),fixed1()*mulPrecision())
     * Test multiply(maxFixedMul()-1,maxFixedMul()) equals multiply(maxFixedMul(),maxFixedMul()-1)
     * Test multiply(maxFixedMul(),maxFixedMul()) returns maxInt256() // Probably not to the last digits
     * Test multiply(maxFixedMul()+1,maxFixedMul()) fails
     * Test multiply(maxFixedMul(),maxFixedMul()+1) fails
     */
    function multiply(int256 x, int256 y) public pure returns (int256) {
        if (x == 0 || y == 0) return 0;
        if (y == fixed1()) return x;
        if (x == fixed1()) return y;

        // Separate into integer and fractional parts
        // x = x1 + x2, y = y1 + y2
        int256 x1 = integer(x) / fixed1();
        int256 x2 = fractional(x);
        int256 y1 = integer(y) / fixed1();
        int256 y2 = fractional(y);
        
        // (x1 + x2) * (y1 + y2) = (x1 * y1) + (x1 * y2) + (x2 * y1) + (x2 * y2)
        int256 x1y1 = x1 * y1;
        if (x1 != 0) assert(x1y1 / x1 == y1); // Overflow x1y1
        
        // x1y1 needs to be multiplied back by fixed1
        // solium-disable-next-line mixedcase
        int256 fixed_x1y1 = x1y1 * fixed1();
        if (x1y1 != 0) assert(fixed_x1y1 / x1y1 == fixed1()); // Overflow x1y1 * fixed1
        x1y1 = fixed_x1y1;

        int256 x2y1 = x2 * y1;
        if (x2 != 0) assert(x2y1 / x2 == y1); // Overflow x2y1

        int256 x1y2 = x1 * y2;
        if (x1 != 0) assert(x1y2 / x1 == y2); // Overflow x1y2

        x2 = x2 / mulPrecision();
        y2 = y2 / mulPrecision();
        int256 x2y2 = x2 * y2;
        if (x2 != 0) assert(x2y2 / x2 == y2); // Overflow x2y2

        // result = fixed1() * x1 * y1 + x1 * y2 + x2 * y1 + x2 * y2 / fixed1();
        int256 result = x1y1;
        result = add(result, x2y1); // Add checks for overflow
        result = add(result, x1y2); // Add checks for overflow
        result = add(result, x2y2); // Add checks for overflow
        return result;
    }
    
    /**
     * @notice 1/x
     * @dev 
     * Test reciprocal(0) fails
     * Test reciprocal(fixed1()) returns fixed1()
     * Test reciprocal(fixed1()*fixed1()) returns 1 // Testing how the fractional is truncated
     * Test reciprocal(2*fixed1()*fixed1()) returns 0 // Testing how the fractional is truncated
     */
    function reciprocal(int256 x) public pure returns (int256) {
        assert(x != 0);
        return (fixed1()*fixed1()) / x; // Can't overflow
    }

    /**
     * @notice x/y. If the dividend is higher than maxFixedDiv() it 
     * might overflow. You can use multiply(x,reciprocal(y)) instead.
     * There is a loss of precision on division for the lower mulPrecision() decimals.
     * @dev 
     * Test divide(fixed1(),0) fails
     * Test divide(maxFixedDiv(),1) = maxFixedDiv()*(10^digits())
     * Test divide(maxFixedDiv()+1,1) throws
     * Test divide(maxFixedDiv(),maxFixedDiv()) returns fixed1()
     */
    function divide(int256 x, int256 y) public pure returns (int256) {
        if (y == fixed1()) return x;
        assert(y != 0);
        assert(y <= maxFixedDivisor());
        return multiply(x, reciprocal(y));
    }
}

// SPDX-License-Identifier: MIT
interface DaiToken {
    function transfer(address dst, uint wad) external returns (bool);
    function transferFrom(address src, address dst, uint wad) external returns (bool);
    function balanceOf(address guy) external view returns (uint);
}

contract PoliTokenFund is usingOraclize {
	// Conditioners
	using SafeMath for uint;
	using FixidityLib for int;


	// Storage
	address admin;

	DaiToken public daiToken; // to interact with DAI token contract, using the interface above
	PoliToken public tokenContract;
	uint public tokenPrice; // price 'p' at which polis can be redeemed for DAI (DAI/poli); each period, this price grows with the lastGrowthRate 'd' like this: p[t1] = p[t0] * (1 + d[t1]/12)
	uint public tokensIssued;

	int public lastPublicOutcome = int(1).newFixed(); // value to be used to calculate the growth of poli holder funds
	int public lastGrowthRate = int(4).newFixed().divide(int(100).newFixed()); // DAI rate (annualized) in 10^24, to compound per issued poli monthly (translates to 0.04, initially)
	uint public lastGrowthTime = now;
	uint public capitalizationRatio = uint(int(1).newFixed()); // the degree to which this contract is funded; 1*10^24 == 100% funded


	// Transaction Events
	event Sell(address _buyer, uint _amount);
  	event Paid(address indexed _from, uint _value);


	// Provable Events
	event NewProvableQuery(string _description);
	event NewPublicOutcome(string _outcome);


	// Constructor
	constructor(DaiToken _daiContract, PoliToken _tokenContract, int _tokenPrice) public {
		// initialize properties
		admin = msg.sender;
		//OAR = OraclizeAddrResolverI(0x6f485C8BF6fc43eA212E93BBF8ce046C7f1cb475); // used in local testing: instantiated after successfully configuring the Ethereum bridge
		tokenContract = _tokenContract;
		tokenPrice = uint(_tokenPrice.newFixed());
		daiToken = DaiToken(_daiContract); // to enable purchases and sales in DAI; this address is the Ethereum Mainnet MCD-DAI contract address
	}


	/// @notice Any funds sent to this function will be unrecoverable
	function () external payable {
	    emit Paid(msg.sender, msg.value);
	}


	// Transaction Methods
  	function buyTokens(uint _poliAmount) external returns (bool success) {
		uint _daiAmount = toDAI(_poliAmount);

		// ensure that sale takes place within the purchase/sale window: within 3 days following a priceUpdate (259,200 seconds)
		require(diffDays(lastGrowthTime, now) <= 3);

		// ensure that poliFund has the required balance to transfer to buyer
	    require(tokenContract.balanceOf(address(this)) >= _poliAmount);
		
		// execute the purchase
		require(daiToken.transferFrom(msg.sender, address(this), _daiAmount));
		require(tokenContract.transfer(msg.sender, _poliAmount));

	    tokensIssued += _poliAmount;

		emit Sell(msg.sender, _poliAmount);
		return true;
	}

	function sellTokens(uint _poliAmount) external returns (bool success) {
		uint _daiAmount = toDAI(_poliAmount);

		// ensure that sale takes place within the purchase/sale window: within 3 days following a priceUpdate
		require(diffDays(lastGrowthTime, now) <= 3);

		// ensure that poliFund has the required balance to transfer to buyer
		require(daiToken.balanceOf(address(this)) >= _daiAmount);

		// execute the sale - paying the seller first
		require(tokenContract.transferFrom(msg.sender, address(this), _poliAmount));
		require(daiToken.transfer(msg.sender, _daiAmount));

		tokensIssued -= _poliAmount;

		emit Sell(address(this), _poliAmount);
		return true;
	}


	// Exchange Rate Methods
	function accrueGrowth() public returns (bool success) {
		// permit only the admin to cause the poli to accrue growth
		require(msg.sender == admin);

		// make a usingProvable call to the given public outcome (e.g., global temperatures)
		updatePublicOutcome();

		return true;
	}

	function updatePublicOutcome() private {
		if (oraclize_getPrice("URL") > address(this).balance) {
            emit NewProvableQuery("Provable query was NOT sent, please add some ETH to cover for the query fee");
        } else {
            // calculate query month string
            string memory _queryIndex = getOracleQueryIndex();

        	// fire off oracle query - good only through 2020
            string memory _jsonQueryStr = append("xml(https://www.ncdc.noaa.gov/cag/global/time-series/globe/land_ocean/all/12/1880-2020/data.xml).dataCollection.data.", _queryIndex, ".value");
       		oraclize_query("URL", _jsonQueryStr);
       		emit NewProvableQuery("Provable query was sent, standing by for the answer..");
        }
	}

	// __callback is called only in updatePublicOutcome(), which itself is only called by accrueGrowth()
	function __callback(bytes32 _queryId, string memory _result) public {
		require(msg.sender == oraclize_cbAddress());
		emit NewPublicOutcome(_result);

		// parse lastPublicOutcome
		lastPublicOutcome = parseSignedInt(_result, 2);

		// calculate the last growth rate
		lastGrowthRate = calculateLastGrowthRate();

		// update poli price
		tokenPrice = updatePrice();

		// update last growth date
		lastGrowthTime = now;
		
		// update capitalizationRatio
		capitalizationRatio = updateCapitalizationRatio();
	}


	// Exchange Rate Helpers
	function toDAI(uint _poliAmount) internal view returns (uint dai) {
	    int _dai = ((int(_poliAmount).newFixed()).multiply(int(tokenPrice))).convertFixed(24, 18); // Poli prices are stored in 24 digits; DAI has 18 digits
	    return uint(_dai);
	}

	function calculateLastGrowthRate() internal view returns (int rate) {
  		// annualized growth rate per poli
  		// r = (20% - 16% * [anomaly in global average surface temperature in degrees Celsius])
  		int _yIntercept = int(20).newFixed().divide(int(100).newFixed());
  		int _slope = int(16).newFixed().divide(int(100).newFixed());
  		int _rate = _yIntercept.subtract(lastPublicOutcome.multiply(_slope));
  		return _rate;
  	}

  	function updatePrice() internal view returns (uint price) {
  		int _price = int(tokenPrice).multiply((lastGrowthRate.divide((int(12).newFixed())).add(1000000000000000000000000)));
  		return uint(_price);
  	}

  	function updateCapitalizationRatio() internal view returns (uint ratio) {
  		int _liabilities = int(tokenPrice).multiply(int(tokenContract.totalSupply().sub(tokenContract.balanceOf(address(this))).sub(tokenContract.balanceOf(admin))).newFixed()); // in DAI
  		if (_liabilities == 0) return 1000000000000000000000000; // if no liabilities, return "100%"

  		int _assets = int(daiToken.balanceOf(address(this))).newFixed(); // in DAI
  		int _ratio = _assets.divide(_liabilities);
  		return uint(_ratio);
  	}


  	// Other Helpers
  	function append(string memory a, string memory b, string memory c) internal pure returns (string memory d) {
    	return string(abi.encodePacked(a, b, c));
	}

	function getOracleQueryIndex() internal view returns (string memory query) {
		uint _firstUpdateIndex = 1683; // index number corresponding to the May 12th, 11:00am EDT release of the monthly NOAA data
		uint _firstUpdateDateTime = 1589295600; // unix timestamp corresponding to the May 12th, 11:00am EDT release of the monthly NOAA data
		uint _daysSinceFirstUpdate = diffDays(_firstUpdateDateTime, now);
		uint _roundedMonthsSinceFirstUpdate = uint(_daysSinceFirstUpdate) / 30; // casting explicitly as uint here gives the floor of the quotient using integer division
		uint _queryIndex = _firstUpdateIndex + _roundedMonthsSinceFirstUpdate; // this should increment by 1 each month, starting after the May 12, 2020 release, which itself corresponds to "1683"
		string memory _queryIndexStr = uint2str(_queryIndex);
		return _queryIndexStr;
	}

    function diffDays(uint fromTimestamp, uint toTimestamp) internal pure returns (uint _days) {
        require(fromTimestamp <= toTimestamp);
        uint _hoursPerDay = 24;
        uint _secondsPerDay = _hoursPerDay.mul(60).mul(60);
        _days = (toTimestamp.sub(fromTimestamp)) / _secondsPerDay;
    }

    function parseSignedInt(string memory _str, uint _digits) internal pure returns (int _int) {
    	string memory _unsignedStr = "";
    	uint _unsignedInt = 0;
    	int _signedInt = 0;
    	int _signedIntFixed = 0;
    	string memory _posNeg = getPosNeg(_str);
    	if (compareStrings(_posNeg, "")) {
    		_signedInt = int(parseInt(_str, _digits));
    	}
    	else {
    		_unsignedStr = substring(_str, 1, bytes(_str).length);
    		_unsignedInt = parseInt(_unsignedStr, _digits);
    		_signedInt = int(_unsignedInt).multiply(-1000000000000000000000000);
    	}
    	_signedIntFixed = (_signedInt.newFixed()).divide((int(10**_digits)).newFixed()); // turn into int 10^24, then scale for _digits, again
    	return _signedIntFixed;
    }

    function getPosNeg(string memory _str) internal pure returns (string memory sign) {
    	string memory _firstChar = substring(_str, 0, 1);
    	string memory _sign = "";
    	if (compareStrings(_firstChar, "-")) {
    		_sign = "-";
    	}
    	return _sign;
    } 

    function substring(string memory str, uint startIndex, uint endIndex) internal pure returns (string memory substr) {
	    bytes memory strBytes = bytes(str);
	    bytes memory result = new bytes(endIndex-startIndex);
	    for(uint i = startIndex; i < endIndex; i++) {
	        result[i-startIndex] = strBytes[i];
	    }
	    return string(result);
	}

	function compareStrings (string memory a, string memory b) internal pure returns (bool equivalent) {
  		return (keccak256(abi.encodePacked((a))) == keccak256(abi.encodePacked((b))) );
    }
}