pragma solidity ^0.4.24;

  /**
   * @title ERC20Basic
   * @dev Simpler version of ERC20 interface
   * @dev see https://github.com/ethereum/EIPs/issues/179
   */
  contract ERC20Basic {
    function totalSupply() public view returns (uint256);
    function balanceOf(address who) public view returns (uint256);
    function transfer(address to, uint256 value) public returns (bool);
    event Transfer(address indexed from, address indexed to, uint256 value);
  }

  /**
   * @title ERC20 interface
   * @dev see https://github.com/ethereum/EIPs/issues/20
   */
  contract ERC20 is ERC20Basic {
    function allowance(address owner, address spender) public view returns (uint256);
    function transferFrom(address from, address to, uint256 value) public returns (bool);
    function approve(address spender, uint256 value) public returns (bool);
    event Approval(address indexed owner, address indexed spender, uint256 value);
  }

  /**
   * @title SafeMath
   * @dev Math operations with safety checks that throw on error
   * @notice https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/contracts/math/SafeMath.sol
   */
  library SafeMath {
  	/**
  	 * SafeMath mul function
  	 * @dev function for safe multiply, throws on overflow.
  	 **/
  	function mul(uint256 a, uint256 b) internal pure returns (uint256) {
  		uint256 c = a * b;
  		assert(a == 0 || c / a == b);
  		return c;
  	}

  	/**
  	 * SafeMath div funciotn
  	 * @dev function for safe devide, throws on overflow.
  	 **/
  	function div(uint256 a, uint256 b) internal pure returns (uint256) {
  		uint256 c = a / b;
  		return c;
  	}

  	/**
  	 * SafeMath sub function
  	 * @dev function for safe subtraction, throws on overflow.
  	 **/
  	function sub(uint256 a, uint256 b) internal pure returns (uint256) {
  		assert(b <= a);
  		return a - b;
  	}

  	/**
  	 * SafeMath add function
  	 * @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;
  	}
  }

  /**
   * @title Basic token
   * @dev Basic version of StandardToken, with no allowances.
   */
  contract BasicToken is ERC20Basic {
    using SafeMath for uint256;

    mapping(address => uint256) balances;

    uint256 totalSupply_;

    /**
    * @dev total number of tokens in existence
    */
    function totalSupply() public view returns (uint256) {
      return totalSupply_;
    }

    /**
    * @dev transfer token for a specified address
    * @param _to The address to transfer to.
    * @param _value The amount to be transferred.
    */
    function transfer(address _to, uint256 _value) public returns (bool) {
      require(_to != address(0));
      require(_value <= balances[msg.sender]);

      balances[msg.sender] = balances[msg.sender].sub(_value);
      balances[_to] = balances[_to].add(_value);
      emit Transfer(msg.sender, _to, _value);
      return true;
    }

    /**
    * @dev Gets the balance of the specified address.
    * @param _owner The address to query the the balance of.
    * @return An uint256 representing the amount owned by the passed address.
    */
    function balanceOf(address _owner) public view returns (uint256) {
      return balances[_owner];
    }

  }

  /**
   * @title Standard ERC20 token
   *
   * @dev Implementation of the basic standard token.
   * @dev https://github.com/ethereum/EIPs/issues/20
   * @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
   */
  contract StandardToken is ERC20, BasicToken {

    mapping (address => mapping (address => uint256)) internal allowed;

    /**
     * @dev Transfer tokens from one address to another
     * @param _from address The address which you want to send tokens from
     * @param _to address The address which you want to transfer to
     * @param _value uint256 the amount of tokens to be transferred
     */
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
      require(_to != address(0));
      require(_value <= balances[_from]);
      require(_value <= allowed[_from][msg.sender]);

      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;
    }

    /**
     * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
     *
     * Beware that changing an allowance with this method brings the risk that someone may use both the old
     * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
     * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     * @param _spender The address which will spend the funds.
     * @param _value The amount of tokens to be spent.
     */
    function approve(address _spender, uint256 _value) public returns (bool) {
      allowed[msg.sender][_spender] = _value;
      emit Approval(msg.sender, _spender, _value);
      return true;
    }

    /**
     * @dev Function to check the amount of tokens that an owner allowed to a spender.
     * @param _owner address The address which owns the funds.
     * @param _spender address The address which will spend the funds.
     * @return A uint256 specifying the amount of tokens still available for the spender.
     */
    function allowance(address _owner, address _spender) public view returns (uint256) {
      return allowed[_owner][_spender];
    }

    /**
     * @dev Increase the amount of tokens that an owner allowed to a spender.
     *
     * approve should be called when allowed[_spender] == 0. To increment
     * allowed value is better to use this function to avoid 2 calls (and wait until
     * the first transaction is mined)
     * From MonolithDAO Token.sol
     * @param _spender The address which will spend the funds.
     * @param _addedValue The amount of tokens to increase the allowance by.
     */
    function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
      allowed[msg.sender][_spender] = (
        allowed[msg.sender][_spender].add(_addedValue));
      emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
      return true;
    }

    /**
     * @dev Decrease the amount of tokens that an owner allowed to a spender.
     *
     * approve should be called when allowed[_spender] == 0. To decrement
     * allowed value is better to use this function to avoid 2 calls (and wait until
     * the first transaction is mined)
     * From MonolithDAO Token.sol
     * @param _spender The address which will spend the funds.
     * @param _subtractedValue The amount of tokens to decrease the allowance by.
     */
    function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
      uint oldValue = allowed[msg.sender][_spender];

      if (_subtractedValue > oldValue) {
        allowed[msg.sender][_spender] = 0;
      } else {
        allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
      }

      emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
      return true;
    }

  }

  /**
   * @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 transfer control of the contract to a newOwner.
     * @param newOwner The address to transfer ownership to.
     */
    function transferOwnership(address newOwner) public onlyOwner {
      require(newOwner != address(0));
      emit OwnershipTransferred(owner, newOwner);
      owner = newOwner;
    }

    /**
     * @dev Allows the current owner to relinquish control of the contract.
     */
    function renounceOwnership() public onlyOwner {
      emit OwnershipRenounced(owner);
      owner = address(0);
    }
  }



  /**
   * @title Pausable token
   * @dev StandardToken modified with pausable transfers.
   **/
  contract CucunToken is StandardToken, Ownable {
      string public name;// = "Cucu Token";
      string public symbol;// = "CUCU";
      uint256 public decimals;// = 8;
      uint256 public initial_supply;// = 100000000000;// 1000 억
      uint lastActionId = 0;
      bool public isPauseOn = false;

      modifier ifNotPaused(){
        require(!isPauseOn || msg.sender == owner);
        _;
      }

      function _doPause(uint act) public{
        lastActionId = act;
        require(msg.sender == owner);
        isPauseOn = true;
      }

      function _doUnpause(uint act) public{
        lastActionId = act;
        require(msg.sender == owner);
        isPauseOn = false;
      }

      /**
       * @dev Transfer tokens when not paused
       **/
      function transfer(address _to, uint256 _value) public ifNotPaused returns (bool) {
          return super.transfer(_to, _value);
      }

      /**
       * @dev transferFrom function to tansfer tokens when token is not paused
       **/
      function transferFrom(address _from, address _to, uint256 _value) public ifNotPaused returns (bool) {
          return super.transferFrom(_from, _to, _value);
      }

      /**
       * @dev approve spender when not paused
       **/
      function approve(address _spender, uint256 _value) public ifNotPaused returns (bool) {
          return super.approve(_spender, _value);
      }

      /**
       * @dev increaseApproval of spender when not paused
       **/
      function increaseApproval(address _spender, uint _addedValue) public ifNotPaused returns (bool success) {
          return super.increaseApproval(_spender, _addedValue);
      }

      /**
       * @dev decreaseApproval of spender when not paused
       **/
      function decreaseApproval(address _spender, uint _subtractedValue) public ifNotPaused returns (bool success) {
          return super.decreaseApproval(_spender, _subtractedValue);
      }


      // Mint more tokens
      function _mint(uint mint_amt) public onlyOwner{
          totalSupply_ = totalSupply_.add(mint_amt);
          balances[owner] = balances[owner].add(mint_amt);
      }

      /**
     * Pausable Token Constructor
     * @dev Create and issue tokens to msg.sender.
     */
    constructor() public {
      name = "Cucu Token";
      symbol = "CUCU";
      decimals = 8;
      initial_supply = 10000000000000000000;

      totalSupply_ = initial_supply;
      balances[msg.sender] = initial_supply;
    }
  }