pragma solidity ^0.4.24;

// <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.
*/

// This api is currently targeted at 0.4.18, please import oraclizeAPI_pre0.4.sol or oraclizeAPI_0.4 where necessary

// Incompatible compiler version... please select one stated within pragma solidity or use different oraclizeAPI version

contract OraclizeI {
    address public cbAddress;
    function query(uint _timestamp, string _datasource, string _arg) external payable returns (bytes32 _id);
    function query_withGasLimit(uint _timestamp, string _datasource, string _arg, uint _gaslimit) external payable returns (bytes32 _id);
    function query2(uint _timestamp, string _datasource, string _arg1, string _arg2) public payable returns (bytes32 _id);
    function query2_withGasLimit(uint _timestamp, string _datasource, string _arg1, string _arg2, uint _gaslimit) external payable returns (bytes32 _id);
    function queryN(uint _timestamp, string _datasource, bytes _argN) public payable returns (bytes32 _id);
    function queryN_withGasLimit(uint _timestamp, string _datasource, bytes _argN, uint _gaslimit) external payable returns (bytes32 _id);
    function getPrice(string _datasource) public returns (uint _dsprice);
    function getPrice(string _datasource, uint gaslimit) public returns (uint _dsprice);
    function setProofType(byte _proofType) external;
    function setCustomGasPrice(uint _gasPrice) external;
    function randomDS_getSessionPubKeyHash() external constant returns(bytes32);
}

contract OraclizeAddrResolverI {
    function getAddress() public returns (address _addr);
}

/*
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 Buffer {
    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);
        // Allocate space for the buffer data
        buf.capacity = capacity;
        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) {
        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 data) internal pure returns(buffer memory) {
        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 {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Length of existing buffer data
            let buflen := mload(bufptr)
            // Start address = buffer address + buffer length + sizeof(buffer length)
            dest := add(add(bufptr, buflen), 32)
            // Update buffer length
            mstore(bufptr, add(buflen, mload(data)))
            src := add(data, 32)
        }

        // Copy word-length chunks while possible
        for(; len >= 32; len -= 32) {
            assembly {
                mstore(dest, mload(src))
            }
            dest += 32;
            src += 32;
        }

        // Copy remaining bytes
        uint mask = 256 ** (32 - len) - 1;
        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 {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Length of existing buffer data
            let buflen := mload(bufptr)
            // Address = buffer address + buffer length + sizeof(buffer length)
            let dest := add(add(bufptr, buflen), 32)
            mstore8(dest, data)
            // Update buffer length
            mstore(bufptr, add(buflen, 1))
        }
    }

    /**
     * @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) {
        if(len + buf.buf.length > buf.capacity) {
            resize(buf, max(buf.capacity, len) * 2);
        }

        uint mask = 256 ** len - 1;
        assembly {
            // Memory address of the buffer data
            let bufptr := mload(buf)
            // Length of existing buffer data
            let buflen := mload(bufptr)
            // Address = buffer address + buffer length + sizeof(buffer length) + len
            let dest := add(add(bufptr, buflen), len)
            mstore(dest, or(and(mload(dest), not(mask)), data))
            // Update buffer length
            mstore(bufptr, add(buflen, len))
        }
        return buf;
    }
}

library CBOR {
    using Buffer for Buffer.buffer;

    uint8 private constant MAJOR_TYPE_INT = 0;
    uint8 private constant MAJOR_TYPE_NEGATIVE_INT = 1;
    uint8 private constant MAJOR_TYPE_BYTES = 2;
    uint8 private constant MAJOR_TYPE_STRING = 3;
    uint8 private constant MAJOR_TYPE_ARRAY = 4;
    uint8 private constant MAJOR_TYPE_MAP = 5;
    uint8 private constant MAJOR_TYPE_CONTENT_FREE = 7;

    function encodeType(Buffer.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(Buffer.buffer memory buf, uint8 major) private pure {
        buf.append(uint8((major << 5) | 31));
    }

    function encodeUInt(Buffer.buffer memory buf, uint value) internal pure {
        encodeType(buf, MAJOR_TYPE_INT, value);
    }

    function encodeInt(Buffer.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(Buffer.buffer memory buf, bytes value) internal pure {
        encodeType(buf, MAJOR_TYPE_BYTES, value.length);
        buf.append(value);
    }

    function encodeString(Buffer.buffer memory buf, string value) internal pure {
        encodeType(buf, MAJOR_TYPE_STRING, bytes(value).length);
        buf.append(bytes(value));
    }

    function startArray(Buffer.buffer memory buf) internal pure {
        encodeIndefiniteLengthType(buf, MAJOR_TYPE_ARRAY);
    }

    function startMap(Buffer.buffer memory buf) internal pure {
        encodeIndefiniteLengthType(buf, MAJOR_TYPE_MAP);
    }

    function endSequence(Buffer.buffer memory buf) internal pure {
        encodeIndefiniteLengthType(buf, MAJOR_TYPE_CONTENT_FREE);
    }
}

/*
End solidity-cborutils
 */

contract usingOraclize {
    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_TLSNotary = 0x10;
    byte constant proofType_Ledger = 0x30;
    byte constant proofType_Android = 0x40;
    byte constant proofType_Native = 0xF0;
    byte constant proofStorage_IPFS = 0x01;
    uint8 constant networkID_auto = 0;
    uint8 constant networkID_mainnet = 1;
    uint8 constant networkID_testnet = 2;
    uint8 constant networkID_morden = 2;
    uint8 constant networkID_consensys = 161;

    OraclizeAddrResolverI OAR;

    OraclizeI oraclize;
    modifier oraclizeAPI {
        if((address(OAR)==0)||(getCodeSize(address(OAR))==0))
            oraclize_setNetwork(networkID_auto);

        if(address(oraclize) != OAR.getAddress())
            oraclize = OraclizeI(OAR.getAddress());

        _;
    }
    modifier coupon(string code){
        oraclize = OraclizeI(OAR.getAddress());
        _;
    }

    function oraclize_setNetwork(uint8 networkID) internal returns(bool){
      return oraclize_setNetwork();
      networkID; // silence the warning and remain backwards compatible
    }
    function oraclize_setNetwork() internal returns(bool){
        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(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;
    }

    function __callback(bytes32 myid, string result) public {
        __callback(myid, result, new bytes(0));
    }
    function __callback(bytes32 myid, string result, bytes proof) public {
      return;
      myid; result; proof; // Silence compiler warnings
    }

    function oraclize_getPrice(string datasource) oraclizeAPI internal returns (uint){
        return oraclize.getPrice(datasource);
    }

    function oraclize_getPrice(string datasource, uint gaslimit) oraclizeAPI internal returns (uint){
        return oraclize.getPrice(datasource, gaslimit);
    }

    function oraclize_query(string datasource, string 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 datasource, string 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 datasource, string 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 datasource, string 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 datasource, string arg1, string 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 datasource, string arg1, string 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 datasource, string arg1, string 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 datasource, string arg1, string 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 datasource, string[] 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 datasource, string[] 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 datasource, string[] 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 datasource, string[] 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 datasource, string[1] 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 datasource, string[1] 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 datasource, string[1] 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 datasource, string[1] 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 datasource, string[2] 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 datasource, string[2] 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 datasource, string[2] 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 datasource, string[2] 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 datasource, string[3] 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 datasource, string[3] 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 datasource, string[3] 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 datasource, string[3] 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 datasource, string[4] 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 datasource, string[4] 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 datasource, string[4] 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 datasource, string[4] 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 datasource, string[5] 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 datasource, string[5] 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 datasource, string[5] 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 datasource, string[5] 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 datasource, bytes[] 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 datasource, bytes[] 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 datasource, bytes[] 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 datasource, bytes[] 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 datasource, bytes[1] 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 datasource, bytes[1] 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 datasource, bytes[1] 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 datasource, bytes[1] 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 datasource, bytes[2] 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 datasource, bytes[2] 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 datasource, bytes[2] 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 datasource, bytes[2] 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 datasource, bytes[3] 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 datasource, bytes[3] 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 datasource, bytes[3] 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 datasource, bytes[3] 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 datasource, bytes[4] 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 datasource, bytes[4] 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 datasource, bytes[4] 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 datasource, bytes[4] 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 datasource, bytes[5] 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 datasource, bytes[5] 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 datasource, bytes[5] 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 datasource, bytes[5] 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_cbAddress() oraclizeAPI internal returns (address){
        return oraclize.cbAddress();
    }
    function oraclize_setProof(byte proofP) oraclizeAPI internal {
        return oraclize.setProofType(proofP);
    }
    function oraclize_setCustomGasPrice(uint gasPrice) oraclizeAPI internal {
        return oraclize.setCustomGasPrice(gasPrice);
    }

    function oraclize_randomDS_getSessionPubKeyHash() oraclizeAPI internal returns (bytes32){
        return oraclize.randomDS_getSessionPubKeyHash();
    }

    function getCodeSize(address _addr) constant internal returns(uint _size) {
        assembly {
            _size := extcodesize(_addr)
        }
    }

    function parseAddr(string _a) internal pure returns (address){
        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(tmp[i]);
            b2 = uint160(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 _a, string _b) internal pure returns (int) {
        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 _haystack, string _needle) internal pure returns (int) {
        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 _a, string _b, string _c, string _d, string _e) internal pure returns (string) {
        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;
        for (uint 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 strConcat(string _a, string _b, string _c, string _d) internal pure returns (string) {
        return strConcat(_a, _b, _c, _d, "");
    }

    function strConcat(string _a, string _b, string _c) internal pure returns (string) {
        return strConcat(_a, _b, _c, "", "");
    }

    function strConcat(string _a, string _b) internal pure returns (string) {
        return strConcat(_a, _b, "", "", "");
    }

    // parseInt
    function parseInt(string _a) internal pure returns (uint) {
        return parseInt(_a, 0);
    }

    // parseInt(parseFloat*10^_b)
    function parseInt(string _a, uint _b) internal pure returns (uint) {
        bytes memory bresult = bytes(_a);
        uint mint = 0;
        bool decimals = false;
        for (uint i=0; i<bresult.length; i++){
            if ((bresult[i] >= 48)&&(bresult[i] <= 57)){
                if (decimals){
                   if (_b == 0) break;
                    else _b--;
                }
                mint *= 10;
                mint += uint(bresult[i]) - 48;
            } else if (bresult[i] == 46) decimals = true;
        }
        if (_b > 0) mint *= 10**_b;
        return mint;
    }

    function uint2str(uint i) internal pure returns (string){
        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(48 + i % 10);
            i /= 10;
        }
        return string(bstr);
    }

    using CBOR for Buffer.buffer;
    function stra2cbor(string[] arr) internal pure returns (bytes) {
        safeMemoryCleaner();
        Buffer.buffer memory buf;
        Buffer.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[] arr) internal pure returns (bytes) {
        safeMemoryCleaner();
        Buffer.buffer memory buf;
        Buffer.init(buf, 1024);
        buf.startArray();
        for (uint i = 0; i < arr.length; i++) {
            buf.encodeBytes(arr[i]);
        }
        buf.endSequence();
        return buf.buf;
    }

    string oraclize_network_name;
    function oraclize_setNetworkName(string _network_name) internal {
        oraclize_network_name = _network_name;
    }

    function oraclize_getNetworkName() internal view returns (string) {
        return oraclize_network_name;
    }

    function oraclize_newRandomDSQuery(uint _delay, uint _nbytes, uint _customGasLimit) internal returns (bytes32){
        require((_nbytes > 0) && (_nbytes <= 32));
        // Convert from seconds to ledger timer ticks
        _delay *= 10;
        bytes memory nbytes = new bytes(1);
        nbytes[0] = byte(_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 relaxed random contract under ethereum-examples repo
            // for an idea on how to override and replace comit hash vars
            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(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;
    }

    mapping(bytes32=>bytes32) oraclize_randomDS_args;
    mapping(bytes32=>bool) oraclize_randomDS_sessionKeysHashVerified;

    function verifySig(bytes32 tosignh, bytes dersig, bytes pubkey) internal returns (bool){
        bool sigok;
        address signer;

        bytes32 sigr;
        bytes32 sigs;

        bytes memory sigr_ = new bytes(32);
        uint offset = 4+(uint(dersig[3]) - 0x20);
        sigr_ = copyBytes(dersig, offset, 32, sigr_, 0);
        bytes memory sigs_ = new bytes(32);
        offset += 32 + 2;
        sigs_ = copyBytes(dersig, offset+(uint(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(keccak256(pubkey)) == signer) return true;
        else {
            (sigok, signer) = safer_ecrecover(tosignh, 28, sigr, sigs);
            return (address(keccak256(pubkey)) == signer);
        }
    }

    function oraclize_randomDS_proofVerify__sessionKeyValidity(bytes proof, uint sig2offset) internal returns (bool) {
        bool sigok;

        // Step 6: verify the attestation signature, APPKEY1 must sign the sessionKey from the correct ledger app (CODEHASH)
        bytes memory sig2 = new bytes(uint(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(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 == false) return false;


        // 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(proof[3+65+1])+2);
        copyBytes(proof, 3+65, sig3.length, sig3, 0);

        sigok = verifySig(sha256(tosign3), sig3, LEDGERKEY);

        return sigok;
    }

    modifier oraclize_randomDS_proofVerify(bytes32 _queryId, string _result, bytes _proof) {
        // Step 1: the prefix has to match 'LP\x01' (Ledger Proof version 1)
        require((_proof[0] == "L") && (_proof[1] == "P") && (_proof[2] == 1));

        bool proofVerified = oraclize_randomDS_proofVerify__main(_proof, _queryId, bytes(_result), oraclize_getNetworkName());
        require(proofVerified);

        _;
    }

    function oraclize_randomDS_proofVerify__returnCode(bytes32 _queryId, string _result, bytes _proof) internal returns (uint8){
        // Step 1: the prefix has to match 'LP\x01' (Ledger Proof version 1)
        if ((_proof[0] != "L")||(_proof[1] != "P")||(_proof[2] != 1)) return 1;

        bool proofVerified = oraclize_randomDS_proofVerify__main(_proof, _queryId, bytes(_result), oraclize_getNetworkName());
        if (proofVerified == false) return 2;

        return 0;
    }

    function matchBytes32Prefix(bytes32 content, bytes prefix, uint n_random_bytes) internal pure returns (bool){
        bool match_ = true;

        require(prefix.length == n_random_bytes);

        for (uint256 i=0; i< n_random_bytes; i++) {
            if (content[i] != prefix[i]) match_ = false;
        }

        return match_;
    }

    function oraclize_randomDS_proofVerify__main(bytes proof, bytes32 queryId, bytes result, string context_name) internal returns (bool){

        // Step 2: the unique keyhash has to match with the sha256 of (context name + queryId)
        uint ledgerProofLength = 3+65+(uint(proof[3+65+1])+2)+32;
        bytes memory keyhash = new bytes(32);
        copyBytes(proof, ledgerProofLength, 32, keyhash, 0);
        if (!(keccak256(keyhash) == keccak256(sha256(context_name, queryId)))) return false;

        bytes memory sig1 = new bytes(uint(proof[ledgerProofLength+(32+8+1+32)+1])+2);
        copyBytes(proof, ledgerProofLength+(32+8+1+32), sig1.length, sig1, 0);

        // 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(proof[ledgerProofLength+32+8]))) return false;

        // 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(commitmentSlice1, sessionPubkeyHash)){ //unonce, nbytes and sessionKeyHash match
            delete oraclize_randomDS_args[queryId];
        } else return false;


        // 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] == false){
            oraclize_randomDS_sessionKeysHashVerified[sessionPubkeyHash] = oraclize_randomDS_proofVerify__sessionKeyValidity(proof, sig2offset);
        }

        return oraclize_randomDS_sessionKeysHashVerified[sessionPubkeyHash];
    }

    // the following function has been written by Alex Beregszaszi (@axic), use it under the terms of the MIT license
    function copyBytes(bytes from, uint fromOffset, uint length, bytes to, uint toOffset) internal pure returns (bytes) {
        uint minLength = length + toOffset;

        // Buffer too small
        require(to.length >= minLength); // Should be a better way?

        // NOTE: the offset 32 is added to skip the `size` field of both bytes variables
        uint i = 32 + fromOffset;
        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 (@axic), 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, address) {
        // 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)

            // NOTE: we can reuse the request memory because we deal with
            //       the return code
            ret := call(3000, 1, 0, size, 128, size, 32)
            addr := mload(size)
        }

        return (ret, addr);
    }

    // the following function has been written by Alex Beregszaszi (@axic), use it under the terms of the MIT license
    function ecrecovery(bytes32 hash, bytes sig) internal returns (bool, address) {
        bytes32 r;
        bytes32 s;
        uint8 v;

        if (sig.length != 65)
          return (false, 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, 0);

        return safer_ecrecover(hash, v, r, s);
    }

    function safeMemoryCleaner() internal pure {
        assembly {
            let fmem := mload(0x40)
            codecopy(fmem, codesize, sub(msize, fmem))
        }
    }

}

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
  address public owner;


  event OwnershipRenounced(address indexed previousOwner);
  event OwnershipTransferred(
    address indexed previousOwner,
    address indexed newOwner
  );


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @dev Allows the current owner to relinquish control of the contract.
   */
  function renounceOwnership() public onlyOwner {
    emit OwnershipRenounced(owner);
    owner = address(0);
  }

  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function transferOwnership(address _newOwner) public onlyOwner {
    _transferOwnership(_newOwner);
  }

  /**
   * @dev Transfers control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function _transferOwnership(address _newOwner) internal {
    require(_newOwner != address(0));
    emit OwnershipTransferred(owner, _newOwner);
    owner = _newOwner;
  }
}

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
    // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
    // benefit is lost if 'b' is also tested.
    // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
    if (a == 0) {
      return 0;
    }

    c = a * b;
    assert(c / a == b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    // uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return a / b;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
    c = a + b;
    assert(c >= a);
    return c;
  }
}

interface IOracle {

    /**
    * @notice Returns address of oracle currency (0x0 for ETH)
    */
    function getCurrencyAddress() external view returns(address);

    /**
    * @notice Returns symbol of oracle currency (0x0 for ETH)
    */
    function getCurrencySymbol() external view returns(bytes32);

    /**
    * @notice Returns denomination of price
    */
    function getCurrencyDenominated() external view returns(bytes32);

    /**
    * @notice Returns price - should throw if not valid
    */
    function getPrice() external view returns(uint256);

}

contract PolyOracle is usingOraclize, IOracle, Ownable {
    using SafeMath for uint256;

    string public oracleURL = "json(https://api.coinmarketcap.com/v2/ticker/2496/?convert=USD).data.quotes.USD.price";
    uint256 public sanityBounds = 20*10**16;
    uint256 public gasLimit = 100000;
    uint256 public oraclizeTimeTolerance = 5 minutes;
    uint256 public staleTime = 6 hours;

    uint256 private POLYUSD;
    uint256 public latestUpdate;
    uint256 public latestScheduledUpdate;

    mapping (bytes32 => uint256) requestIds;
    mapping (bytes32 => bool) public ignoreRequestIds;

    mapping (address => bool) public admin;

    bool public freezeOracle;

    event LogPriceUpdated(uint256 _price, uint256 _oldPrice, uint256 _time);
    event LogNewOraclizeQuery(uint256 _time, bytes32 _queryId, string _query);
    event LogAdminSet(address _admin, bool _valid, uint256 _time);

    modifier isAdminOrOwner {
        require(admin[msg.sender] || msg.sender == owner, "Address is not admin or owner");
        _;
    }

    /**
    * @notice Constructor - accepts ETH to initialise a balance for subsequent Oraclize queries
    */
    constructor() payable public {
        // Use 50 gwei for now
        oraclize_setCustomGasPrice(50*10**9);
    }

    /**
    * @notice Oraclize callback (triggered by Oraclize)
    * @param _requestId requestId corresponding to Oraclize query
    * @param _result data returned by Oraclize URL query
    */
    function __callback(bytes32 _requestId, string _result) public {
        require(msg.sender == oraclize_cbAddress(), "Only Oraclize can access this method");
        require(!freezeOracle, "Oracle is frozen");
        require(!ignoreRequestIds[_requestId], "Ignoring requestId");
        require(requestIds[_requestId] >= latestUpdate, "Result is stale");
        require(requestIds[_requestId] <= now + oraclizeTimeTolerance, "Result is early");
        uint256 newPOLYUSD = parseInt(_result, 18);
        uint256 bound = POLYUSD.mul(sanityBounds).div(10**18);
        if (latestUpdate != 0) {
          require(newPOLYUSD <= POLYUSD.add(bound), "Result is too large");
          require(newPOLYUSD >= POLYUSD.sub(bound), "Result is too small");
        }
        latestUpdate = requestIds[_requestId];
        delete requestIds[_requestId];
        emit LogPriceUpdated(newPOLYUSD, POLYUSD, latestUpdate);
        POLYUSD = newPOLYUSD;
    }

    /**
    * @notice Allows owner to schedule future Oraclize calls
    * @param _times UNIX timestamps to schedule Oraclize calls as of. Empty list means trigger an immediate query.
    */
    function schedulePriceUpdatesFixed(uint256[] _times) payable isAdminOrOwner public {
        bytes32 requestId;
        if (_times.length == 0) {
            require(oraclize_getPrice("URL") <= address(this).balance, "Insufficient Funds");
            requestId = oraclize_query("URL", oracleURL, gasLimit);
            requestIds[requestId] = now;
            if (latestScheduledUpdate < requestIds[requestId]) {
                latestScheduledUpdate = requestIds[requestId];
            }
            emit LogNewOraclizeQuery(now, requestId, oracleURL);
        } else {
            require(oraclize_getPrice("URL") * _times.length <= address(this).balance, "Insufficient Funds");
            for (uint256 i = 0; i < _times.length; i++) {
                requestId = oraclize_query(_times[i], "URL", oracleURL, gasLimit);
                requestIds[requestId] = _times[i];
                emit LogNewOraclizeQuery(_times[i], requestId, oracleURL);
            }
            if (latestScheduledUpdate < requestIds[requestId]) {
                latestScheduledUpdate = requestIds[requestId];
            }
        }
    }

    /**
    * @notice Allows owner to schedule future Oraclize calls on a rolling schedule
    * @param _startTime UNIX timestamp for the first scheduled Oraclize query
    * @param _interval how long (in seconds) between each subsequent Oraclize query
    * @param _iters the number of Oraclize queries to schedule.
    */
    function schedulePriceUpdatesRolling(uint256 _startTime, uint256 _interval, uint256 _iters) payable isAdminOrOwner public {
        bytes32 requestId;
        require(oraclize_getPrice("URL") * _iters <= address(this).balance, "Insufficient Funds");
        for (uint256 i = 0; i < _iters; i++) {
            uint256 scheduledTime = _startTime + (i * _interval);
            requestId = oraclize_query(scheduledTime, "URL", oracleURL, gasLimit);
            requestIds[requestId] = scheduledTime;
            emit LogNewOraclizeQuery(scheduledTime, requestId, oracleURL);
        }
        if (latestScheduledUpdate < requestIds[requestId]) {
            latestScheduledUpdate = requestIds[requestId];
        }
    }

    /**
    * @notice Allows owner to manually set POLYUSD price
    * @param _price POLYUSD price
    */
    function setPOLYUSD(uint256 _price) onlyOwner public {
        emit LogPriceUpdated(_price, POLYUSD, now);
        POLYUSD = _price;
        latestUpdate = now;
    }

    /**
    * @notice Allows owner to set oracle to ignore all Oraclize pricce updates
    * @param _frozen true to freeze updates, false to reenable updates
    */
    function setFreezeOracle(bool _frozen) onlyOwner public {
        freezeOracle = _frozen;
    }

    /**
    * @notice Allows owner to set URL used in Oraclize queries
    * @param _oracleURL URL to use
    */
    function setOracleURL(string _oracleURL) onlyOwner public {
        oracleURL = _oracleURL;
    }

    /**
    * @notice Allows owner to set new sanity bounds for price updates
    * @param _sanityBounds sanity bounds as a percentage * 10**16
    */
    function setSanityBounds(uint256 _sanityBounds) onlyOwner public {
        sanityBounds = _sanityBounds;
    }

    /**
    * @notice Allows owner to set new gas price for future Oraclize queries
    * @notice NB - this will only impact newly scheduled Oraclize queries, not future queries which have already been scheduled
    * @param _gasPrice gas price to use for Oraclize callbacks
    */
    function setGasPrice(uint256 _gasPrice) onlyOwner public {
        oraclize_setCustomGasPrice(_gasPrice);
    }

    /**
    * @notice Returns price and corresponding update time
    * @return latest POLYUSD price
    * @return timestamp of latest price update
    */
    function getPriceAndTime() view public returns(uint256, uint256) {
        return (POLYUSD, latestUpdate);
    }

    /**
    * @notice Allows owner to set new gas limit on Oraclize queries
    * @notice NB - this will only impact newly scheduled Oraclize queries, not future queries which have already been scheduled
    * @param _gasLimit gas limit to use for Oraclize callbacks
    */
    function setGasLimit(uint256 _gasLimit) onlyOwner public {
        gasLimit = _gasLimit;
    }

    /**
    * @notice Allows owner to set time after which price is considered stale
    * @param _staleTime elapsed time after which price is considered stale
    */
    function setStaleTime(uint256 _staleTime) onlyOwner public {
        staleTime = _staleTime;
    }

    /**
    * @notice Allows owner to ignore specific requestId results from Oraclize
    * @param _requestIds Oraclize queryIds (as logged out when Oraclize query is scheduled)
    * @param _ignore whether or not they should be ignored
    */
    function setIgnoreRequestIds(bytes32[] _requestIds, bool[] _ignore) onlyOwner public {
        require(_requestIds.length == _ignore.length, "Incorrect parameter lengths");
        for (uint256 i = 0; i < _requestIds.length; i++) {
            ignoreRequestIds[_requestIds[i]] = _ignore[i];
        }
    }

    /**
    * @notice Allows owner to set up admin addresses that can schedule updates
    * @param _admin Admin address
    * @param _valid Whether address should be added or removed from admin list
    */
    function setAdmin(address _admin, bool _valid) onlyOwner public {
        admin[_admin] = _valid;
        emit LogAdminSet(_admin, _valid, now);
    }

    /**
    * @notice Allows owner to set new time tolerance on Oraclize queries
    * @param _oraclizeTimeTolerance amount of time in seconds that an Oraclize query can be early
    */
    function setOraclizeTimeTolerance(uint256 _oraclizeTimeTolerance) onlyOwner public {
        oraclizeTimeTolerance = _oraclizeTimeTolerance;
    }

    /**
    * @notice Returns address of oracle currency (0x0 for ETH)
    */
    function getCurrencyAddress() external view returns(address) {
        return 0x9992eC3cF6A55b00978cdDF2b27BC6882d88D1eC;
    }

    /**
    * @notice Returns symbol of oracle currency (0x0 for ETH)
    */
    function getCurrencySymbol() external view returns(bytes32) {
        return bytes32("POLY");
    }

    /**
    * @notice Returns denomination of price
    */
    function getCurrencyDenominated() external view returns(bytes32) {
        return bytes32("USD");
    }

    /**
    * @notice Returns price - should throw if not valid
    */
    function getPrice() external view returns(uint256) {
        require(latestUpdate >= now - staleTime);
        return POLYUSD;
    }

}