contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  /**
  * @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]); 
    // SafeMath.sub will throw if there is not enough balance. 
    balances[msg.sender] = balances[msg.sender].sub(_value); 
    balances[_to] = balances[_to].add(_value); 
    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 constant returns (uint256 balance) { 
    return balances[_owner]; 
  } 
}
/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
function balanceOf(address _owner) public constant returns (uint256 balance) { 
  return balances[_owner]; 
} 

/** 
 * @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. 
 */