contract Token {

    /* Total amount of tokens */
    uint256 public totalSupply;

    /*
     * Events
     */
    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);

    /*
     * Public functions
     */

    /// @notice send `value` token to `to` from `msg.sender`
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return Whether the transfer was successful or not
    function transfer(address to, uint value) public returns (bool);

    /// @notice send `value` token to `to` from `from` on the condition it is approved by `from`
    /// @param from The address of the sender
    /// @param to The address of the recipient
    /// @param value The amount of token to be transferred
    /// @return Whether the transfer was successful or not
    function transferFrom(address from, address to, uint value) public returns (bool);

    /// @notice `msg.sender` approves `spender` to spend `value` tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @param value The amount of tokens to be approved for transfer
    /// @return Whether the approval was successful or not
    function approve(address spender, uint value) public returns (bool);

    /// @param owner The address from which the balance will be retrieved
    /// @return The balance
    function balanceOf(address owner) public constant returns (uint);

    /// @param owner The address of the account owning tokens
    /// @param spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens allowed to spent
    function allowance(address owner, address spender) public constant returns (uint);
}
function approve(address spender, uint value) public returns (bool);

/// @notice `msg.sender` approves `spender` to spend `value` tokens
/// @param spender The address of the account able to transfer the tokens
/// @param value The amount of tokens to be approved for transfer
/// @return Whether the approval was successful or not