pragma solidity ^0.4.22;

// File: contracts/libraries/SafeMath.sol

/**
 * @dev SafeMath by openzepplin
 */ 
library SafeMath {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        assert(c / a == b);
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        // assert(b > 0); 
        uint256 c = a / b;
        // assert(a == b * c + a % b); 
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        assert(b <= a);
        return a - b;
    }

    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        assert(c >= a);
        return c;
    }
}

// File: contracts/libraries/usingOraclize.sol

// <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
pragma solidity ^0.4.18;

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);
}
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_Android = 0x20;
    byte constant proofType_Ledger = 0x30;
    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);
    }

    function stra2cbor(string[] arr) internal pure returns (bytes) {
            uint arrlen = arr.length;

            // get correct cbor output length
            uint outputlen = 0;
            bytes[] memory elemArray = new bytes[](arrlen);
            for (uint i = 0; i < arrlen; i++) {
                elemArray[i] = (bytes(arr[i]));
                outputlen += elemArray[i].length + (elemArray[i].length - 1)/23 + 3; //+3 accounts for paired identifier types
            }
            uint ctr = 0;
            uint cborlen = arrlen + 0x80;
            outputlen += byte(cborlen).length;
            bytes memory res = new bytes(outputlen);

            while (byte(cborlen).length > ctr) {
                res[ctr] = byte(cborlen)[ctr];
                ctr++;
            }
            for (i = 0; i < arrlen; i++) {
                res[ctr] = 0x5F;
                ctr++;
                for (uint x = 0; x < elemArray[i].length; x++) {
                    // if there's a bug with larger strings, this may be the culprit
                    if (x % 23 == 0) {
                        uint elemcborlen = elemArray[i].length - x >= 24 ? 23 : elemArray[i].length - x;
                        elemcborlen += 0x40;
                        uint lctr = ctr;
                        while (byte(elemcborlen).length > ctr - lctr) {
                            res[ctr] = byte(elemcborlen)[ctr - lctr];
                            ctr++;
                        }
                    }
                    res[ctr] = elemArray[i][x];
                    ctr++;
                }
                res[ctr] = 0xFF;
                ctr++;
            }
            return res;
        }

    function ba2cbor(bytes[] arr) internal pure returns (bytes) {
            uint arrlen = arr.length;

            // get correct cbor output length
            uint outputlen = 0;
            bytes[] memory elemArray = new bytes[](arrlen);
            for (uint i = 0; i < arrlen; i++) {
                elemArray[i] = (bytes(arr[i]));
                outputlen += elemArray[i].length + (elemArray[i].length - 1)/23 + 3; //+3 accounts for paired identifier types
            }
            uint ctr = 0;
            uint cborlen = arrlen + 0x80;
            outputlen += byte(cborlen).length;
            bytes memory res = new bytes(outputlen);

            while (byte(cborlen).length > ctr) {
                res[ctr] = byte(cborlen)[ctr];
                ctr++;
            }
            for (i = 0; i < arrlen; i++) {
                res[ctr] = 0x5F;
                ctr++;
                for (uint x = 0; x < elemArray[i].length; x++) {
                    // if there's a bug with larger strings, this may be the culprit
                    if (x % 23 == 0) {
                        uint elemcborlen = elemArray[i].length - x >= 24 ? 23 : elemArray[i].length - x;
                        elemcborlen += 0x40;
                        uint lctr = ctr;
                        while (byte(elemcborlen).length > ctr - lctr) {
                            res[ctr] = byte(elemcborlen)[ctr - lctr];
                            ctr++;
                        }
                    }
                    res[ctr] = elemArray[i][x];
                    ctr++;
                }
                res[ctr] = 0xFF;
                ctr++;
            }
            return res;
        }


    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)
            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);
    }

}
// </ORACLIZE_API>

// File: contracts/VitalikLotto.sol

contract VitalikLotto is usingOraclize {

    using SafeMath for uint256;

    // events 
    event DividendsWithdrawn(address beneficiary, uint256 ethValue);
    event DividendsReinvested(address beneficiary, uint256 dividends, uint256 tokenAmount);
    event LotteryCreated(uint256 identifier);
    event LotteryWinnerDetermined(address winner, uint256 winnerReward, address triggerer, uint256 triggererReward, uint256 random);
    event RandomRequested(uint256 identifier);
    event TokensPurchased(address beneficiary, uint256 tokenAmount, uint256 ethValue, address referrer);
    event TokensSold(address beneficiary, uint256 tokenAmount, uint256 ethValue);

    struct Lottery {
        bool instantiated;
        uint256 identifier;
        address[] ticketHolders;
        bool completed;
        uint256 reward;
    }

    // administration state variables
    uint256 constant internal ambassadorQuota = 4.8 ether;
    bool public pausedToPublic = true;
    bool public ambassadorMode = true;
    bool public pendingOraclize = false;

    // token state variables
    string constant public name = "Vitalik Lotto Token";
    string constant public symbol = "VLK";
    uint8 constant public decimals = 18;
    
    // game state variables
    uint constant minPurchaseAmount = 1 szabo; //0.000001 ether
    uint constant maxPurchaseAmount = 1000000 ether;
    uint256 constant internal initialTokenPrice = 0.0000001 ether;
    uint256 constant internal tokenIncrement = 0.00000001 ether;
    uint256 constant internal scaleFactor = 2**64;
    uint constant dividendFee = 5; // (1/5) = 20%
    uint constant referralFee = 3; // (1/3) = ~ 30%
    uint256 earningsPerToken;
    uint256 public tokenSupply;
    uint256 public contractBalance;

    // lotto state variables
    uint256 constant requiredLottoParticipants = 19;
    uint256 constant lottoFee = 10; // (1/10) = 10%
    uint256 constant lottoMin = .5 ether; 
    uint256 public lottoBalance;
    uint256 public lottoIdentifier;
    uint256 public lottoQueue;

    // administration mappings
    mapping (address => bool) public administrators;
    mapping (address => bool) public ambassadors;

    // game mappings
    mapping (address => int256) public payouts;
    mapping (address => uint256) internal referralBalance;
    mapping (address => uint256) public tokenBalance;
    mapping (address => address) public referrer; // safer alternative to cookie based referrals

    // lottery mappings
    mapping (uint256 => Lottery) lotteries;
    mapping (bytes32 => bool) lotteryRandomed;
    
    // contract constructor
    constructor() public {
        // grant the contract creator adminstration privileges
        administrators[msg.sender] = true;
        // create the first lottery
        _createLottery();
    }

    function activate() public {
        require(administrators[msg.sender] == true);
        require(pausedToPublic);
        pausedToPublic = false;
    }

    // returns the number of tokens for an user
    function balanceOf(address _user) public view returns(uint256) {
        return tokenBalance[_user];
    }

    function buyPrice() public view returns(uint256) {
        if(tokenSupply == 0) {
            return initialTokenPrice + tokenIncrement;
        } else {
            uint256 ethereum = _tokensToEthereum(1e18);
            uint256 dividends = SafeMath.div(ethereum, dividendFee);
            uint256 taxedEther = SafeMath.add(ethereum, dividends);
            return taxedEther;
        }
    }

    // an administrator can repeal the ambassador mode in case of an 
    // emergency / lack of funding
    function disableAmbassadorMode() public {
        require(administrators[msg.sender] == true);
        require(ambassadorMode);
        ambassadorMode = false;
    }

    // primary purchasing function which allows for a masternode referral
    function fund(address _referrer) public payable {
        require(getCodeSize(msg.sender) == 0);
        require(msg.value > minPurchaseAmount && msg.value < maxPurchaseAmount);
        contractBalance = SafeMath.add(contractBalance, msg.value);
        purchaseTokens(msg.value, _referrer);
    }

    // frontend function to get the referral balance of a user
    function getReferralBalance(address _user) public view returns (uint256) {
        return referralBalance[_user];
    }

    // returns the user's accumulated dividends, including the referral earnings
    function getUserDividends(address _user) public view returns (uint256) {
        return ((uint256) ((int256)(earningsPerToken * tokenBalance[_user]) - payouts[_user]) / scaleFactor) + (referralBalance[_user]);
    }
    
    // public function that allows a token holder to manually trigger the latest lottery
    // this saves on gas and potential failures during the purchase of tokens
    function invokeLottery() public {
        require(tokenBalance[msg.sender] > 0);
        Lottery storage lotto = lotteries[lottoQueue];
        require(lotto.instantiated);
        require(!lotto.completed);
        require(lotto.ticketHolders.length == requiredLottoParticipants);
        require(!pendingOraclize);
        pendingOraclize = true;
        emit RandomRequested(lotto.identifier);
        // generate an oraclize query by calling wolfram alpha
        // both the min and the max are inclusive
        oraclize_query("WolframAlpha", "random number between 0 and 18");
    }

    function purchaseTokens(uint256 _ethValue, address _referrer) contributionPhase() internal returns(uint256) {
        uint256 lottoFunds = SafeMath.div(_ethValue, lottoFee);
        uint256 undividedDividends = SafeMath.div(SafeMath.sub(_ethValue, lottoFunds), dividendFee);
        uint256 referralFunds = SafeMath.div(undividedDividends, referralFee);
        uint256 dividends = SafeMath.sub(undividedDividends, referralFunds);
        uint256 taxedEther = SafeMath.sub(_ethValue, dividends);
        uint256 tokenAmount = _ethereumToTokens(taxedEther);
        uint256 fee = dividends * scaleFactor;

        // if no referrer has been passed to the contract, check to see
        // if the user has already been referred by someone, previously.
        // this will also override a new referral attempt and use the initial referrer
        if(referrer[msg.sender] != 0x0000000000000000000000000000000000000000){
            _referrer = referrer[msg.sender];
        }
        // ensure the referrer has at least 100 tokens; otherwise set the
        // referrer to nilll
        if(tokenBalance[_referrer] < 100e18){
            _referrer = 0x0000000000000000000000000000000000000000;
        }
        // masternode referral check
        if(_referrer != 0x0000000000000000000000000000000000000000 && _referrer != msg.sender && 
            tokenBalance[_referrer] >= 100e18){ // 100 token masternode requirement
            // referrer receives their bonus
            referralBalance[_referrer] = SafeMath.add(referralBalance[_referrer], referralFunds);
            // store the referral for life
            referrer[msg.sender] = _referrer;
        } else {
            // there was no referrer, or the referrer does not have enough tokens
            dividends = SafeMath.add(dividends, referralFunds);
            // recalculate fee 
            fee = dividends * scaleFactor;
        }
        if(tokenSupply > 0){
            tokenSupply = SafeMath.add(tokenSupply, tokenAmount);
            earningsPerToken += (dividends * scaleFactor / (tokenSupply));
            fee = fee - (fee-(tokenAmount * (dividends * scaleFactor / (tokenSupply))));
        } else {
            tokenSupply = tokenAmount;
        }
        // add the lotto funds to the lotto balance
        lottoBalance = SafeMath.add(lottoBalance, lottoFunds);
        tokenBalance[msg.sender] = SafeMath.add(tokenBalance[msg.sender], tokenAmount);
        int256 purchasePayout = (int256)((earningsPerToken * tokenAmount) - fee);
        payouts[msg.sender] += purchasePayout;
        // if the msg.sender contributes .5 ether or more, they are eligible for the lottery
        if(_ethValue >= lottoMin) {
            Lottery storage lotto = lotteries[lottoIdentifier];
            lotto.ticketHolders.push(msg.sender);
            // every 19th lottery entry should trigger the drawing
            if(lotto.ticketHolders.length == requiredLottoParticipants){
                uint256 lottoReward = lottoBalance;
                lottoBalance = 0;
                // set lottery reward
                lotto.reward = lottoReward;
                // increment lottery identifier and create a fresh, empty one
                lottoIdentifier++;
                _createLottery();
            }
        }  
        emit TokensPurchased(msg.sender, tokenAmount, _ethValue, _referrer);
        return tokenAmount;
    }

    function reinvest() public {
        address user = msg.sender;
        uint256 dividends = SafeMath.sub(getUserDividends(user), referralBalance[user]);
        require(dividends > 0);
        payouts[user] += (int256)(dividends * scaleFactor);
        dividends += referralBalance[user];
        referralBalance[user] = 0;
        uint256 tokenAmount = purchaseTokens(dividends, address(0x0));
        emit DividendsReinvested(user, dividends, tokenAmount);
    }

    function sell(uint256 _tokenAmount) public {
        address user = msg.sender;
        require(tokenBalance[user] > 0);
        require(_tokenAmount <= tokenBalance[user]);
        uint256 ethValue = _tokensToEthereum(_tokenAmount);
        uint256 lottoFunds = SafeMath.div(ethValue, lottoFee);
        // add the lotto funds to the lotto balance
        lottoBalance = SafeMath.add(lottoBalance, lottoFunds);
        uint256 dividends = SafeMath.div(SafeMath.sub(ethValue, lottoFunds), dividendFee);
        uint256 taxedEther = SafeMath.sub(ethValue, dividends);
        tokenSupply = SafeMath.sub(tokenSupply, _tokenAmount);
        tokenBalance[user] = SafeMath.sub(tokenBalance[user], _tokenAmount);
        int256 payout = (int256) (earningsPerToken * _tokenAmount + (taxedEther * scaleFactor));
        payouts[user] -= payout;      
        if (tokenSupply > 0) {
            earningsPerToken = SafeMath.add(earningsPerToken, (dividends * scaleFactor) / tokenSupply);
        }
        emit TokensSold(user, _tokenAmount, taxedEther);
    }

    function sellPrice() public view returns(uint256) {
        if(tokenSupply == 0){
            return initialTokenPrice - tokenIncrement;
        } else {
            uint256 ethereum = _tokensToEthereum(1e18);
            uint256 dividends = SafeMath.div(ethereum, dividendFee);
            uint256 taxedEther = SafeMath.sub(ethereum, dividends);
            return taxedEther;
        }
    }

    // administrator can whitelist an administrator
    function setAdministrator(address _user) public {
        require(administrators[msg.sender] == true);
        administrators[_user] = true;
    }

    // administrator can whitelist an ambassador
    function setAmbassador(address _user) public {
        require(administrators[msg.sender] == true);
        ambassadors[_user] = true;
    }

    function totalSupply() public view returns(uint256) {
        return tokenSupply;
    }

    function withdraw() public {
        address user = msg.sender;
        uint256 dividends = SafeMath.sub(getUserDividends(user), referralBalance[user]);
        require(dividends > 0);
        payouts[user] += (int256) (dividends * scaleFactor);
        // reset accumulated referral earnings
        referralBalance[user] = 0;
        dividends += referralBalance[user];
        // update the contract balance
        contractBalance = SafeMath.sub(contractBalance, dividends);
        user.transfer(dividends);
        emit DividendsWithdrawn(user, dividends);
    }

    // purchase tokens by sending funds directly to the contract
    function () payable public {
        require(getCodeSize(msg.sender) == 0);
        // call funding function with a blank referrer
        fund(address(0x0000000000000000000000000000000000000000));
    }

    /*
        MODIFIERS
    */

    // modifier function that checks if only ambassadors can currently contribute
    modifier contributionPhase(){
        if(ambassadorMode) {
            if((contractBalance < ambassadorQuota)) {
                require(ambassadors[msg.sender]);
                _;
            } else {
                ambassadorMode = false;
                _;
            }
        } else {
            require(!pausedToPublic);
            _;
        }
    }

    /*
        INTERNAL FUNCTIONS
    */

    function __callback(bytes32 _queryId, string _result) public {
        require(msg.sender == oraclize_cbAddress());
        require(lotteryRandomed[_queryId] == false);
        Lottery storage lotto = lotteries[lottoQueue];
        require(!lotto.completed);
        uint256 triggererReward;
        uint256 winnerReward;
        address winner;
        address triggerer;
        // parseInt function is available in usingOraclize contract
        uint256 random = uint256(parseInt(_result));
        (winnerReward, triggererReward, winner, triggerer) = _rewardLotteryWinners(lottoQueue, random);
        lottoQueue++;
        lotteryRandomed[_queryId] = true;
        pendingOraclize = false;
        emit LotteryWinnerDetermined(winner, winnerReward, triggerer, triggererReward, random);
    }

    function _createLottery() internal {
        Lottery memory newLotto = Lottery(true, lottoIdentifier, new address[](0), false, 0);
        lotteries[lottoIdentifier] = newLotto;
        emit LotteryCreated(lottoIdentifier);
    }

    function _ethereumToTokens(uint256 _ethereum) internal view returns(uint256) {
        uint256 _tokenPriceInitial = initialTokenPrice * 1e18;
        uint256 tokenAmount = 
         (
            (
                SafeMath.sub(
                    (_sqrt
                        (
                            (_tokenPriceInitial**2)
                            +
                            (2*(tokenIncrement * 1e18)*(_ethereum * 1e18))
                            +
                            (((tokenIncrement)**2)*(tokenSupply**2))
                            +
                            (2*(tokenIncrement)*_tokenPriceInitial*tokenSupply)
                        )
                    ), _tokenPriceInitial
                )
            )/(tokenIncrement)
        )-(tokenSupply)
        ;
        return tokenAmount;
    }

    function _rewardLotteryWinners(uint256 _identifier, uint256 _result) internal returns (uint256, uint256, address, address) {
        Lottery storage lotto = lotteries[_identifier];
        // reward for being the 19th participant
        uint256 triggererFunds = SafeMath.div(lotto.reward, 5);
        // reward for the lucky ticket holder
        uint256 luckyFunds = SafeMath.sub(lotto.reward, triggererFunds);
        // the triggerer is the last index of the array
        address triggerer = lotto.ticketHolders[requiredLottoParticipants - 1];
        address winner = lotto.ticketHolders[_result];
        winner.transfer(luckyFunds);
        triggerer.transfer(triggererFunds);
        contractBalance = SafeMath.sub(contractBalance, lotto.reward);
        lotto.completed = true;
        return (luckyFunds, triggererFunds, winner, triggerer);
    }

    function _sqrt(uint x) internal pure returns (uint y) {
        uint z = (x + 1) / 2;
        y = x;
        while (z < y) {
            y = z;
            z = (x / z + z) / 2;
        }
    }

    function _tokensToEthereum(uint256 _tokens) public view returns(uint256) {
        uint256 tokens = (_tokens + 1e18);
        uint256 supply = (tokenSupply + 1e18);
        uint256 ethValue =
        (
            SafeMath.sub(
                (
                    (
                        (
                            initialTokenPrice +(tokenIncrement * (supply/1e18))
                        )-tokenIncrement
                    )*(tokens - 1e18)
                ),(tokenIncrement*((tokens**2-tokens)/1e18))/2
            )
        /1e18);
        return ethValue;
    }
}