// Vulnerability label: ARTHM
pragma solidity ^0.4.18;
interface tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) external; }
contract Token {
 // Public variables of the token
 string public name;
 string public symbol;
 uint8 public decimals = 18;
 // 18 decimals is the strongly suggested default, avoid changing it
 uint256 public totalSupply;
 // This creates an array with all balances
 mapping (address => uint256) public balanceOf;
 mapping (address => mapping (address => uint256)) public allowance;
 // This generates a public event on the blockchain that will notify clients
 event Transfer(address indexed from, address indexed to, uint256 value);

 // This generates a public event on the blockchain that will notify clients
 event Approval(address indexed _owner, address indexed _spender, uint256 _value);
 // This notifies clients about the amount burnt
 event Burn(address indexed from, uint256 value);
 /**
 * Constructor function
 *
 * Initializes contract with initial supply tokens to the creator of the contract
 */
 function TokenERC20(
 uint256 initialSupply,
 string tokenName,
 string tokenSymbol
 ) public {
 totalSupply = initialSupply * 10 ** uint256(decimals); // Update total supply with the decimal amount
 balanceOf[msg.sender] = totalSupply; // Give the creator all initial tokens
 name = tokenName; // Set the name for display purposes
 symbol = tokenSymbol; // Set the symbol for display purposes
 }
 /**
 * Internal transfer, only can be called by this contract
 */
 function _transfer(address _from, address _to, uint _value) internal {
 // Prevent transfer to 0x0 address. Use burn() instead
 require(_to != 0x0);
 // Check if the sender has enough
 require(balanceOf[_from] >= _value);
 // Check for overflows
 require(balanceOf[_to] + _value >= balanceOf[_to]);
 // Save this for an assertion in the future
 uint previousBalances = balanceOf[_from] + balanceOf[_to];
 // Subtract from the sender
 balanceOf[_from] -= _value;
 // Add the same to the recipient
 balanceOf[_to] += _value;
 emit Transfer(_from, _to, _value);
 // Asserts are used to use static analysis to find bugs in your code. They should never fail
 assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
 }
 /**
 * Transfer tokens
 *
 * Send `_value` tokens to `_to` from your account
 *
 * @param _to The address of the recipient
 * @param _value the amount to send
 */
 function transfer(address _to, uint256 _value) public returns (bool success) {
 _transfer(msg.sender, _to, _value);
 return true;
 }
 /**
 * Transfer tokens from other address
 *
 * Send `_value` tokens to `_to` on behalf of `_from`
 *
 * @param _from The address of the sender
 * @param _to The address of the recipient
 * @param _value the amount to send
 */
 function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
 require(_value <= allowance[_from][msg.sender]); // Check allowance
 allowance[_from][msg.sender] -= _value;
 _transfer(_from, _to, _value);
 return true;
 }
 /**
 * Set allowance for other address
 *
 * Allows `_spender` to spend no more than `_value` tokens on your behalf
 *
 * @param _spender The address authorized to spend
 * @param _value the max amount they can spend
 */
 function approve(address _spender, uint256 _value) public
 returns (bool success) {
 allowance[msg.sender][_spender] = _value;
 emit Approval(msg.sender, _spender, _value);
 return true;
 }
 /**
 * Set allowance for other address and notify
 *
 * Allows `_spender` to spend no more than `_value` tokens on your behalf, and then ping the contract about it
 *
 * @param _spender The address authorized to spend
 * @param _value the max amount they can spend
 * @param _extraData some extra information to send to the approved contract
 */
 function approveAndCall(address _spender, uint256 _value, bytes _extraData)
 public
 returns (bool success) {
 tokenRecipient spender = tokenRecipient(_spender);
 if (approve(_spender, _value)) {
 spender.receiveApproval(msg.sender, _value, this, _extraData);
 return true;
 }
 }
 /**
 * Destroy tokens
 *
 * Remove `_value` tokens from the system irreversibly
 *
 * @param _value the amount of money to burn
 */
 function burn(uint256 _value) public returns (bool success) {
 require(balanceOf[msg.sender] >= _value); // Check if the sender has enough
 balanceOf[msg.sender] -= _value; // Subtract from the sender
 totalSupply -= _value; // Updates totalSupply
 emit Burn(msg.sender, _value);
 return true;
 }
 /**
 * Destroy tokens from other account
 *
 * Remove `_value` tokens from the system irreversibly on behalf of `_from`.
 *
 * @param _from the address of the sender
 * @param _value the amount of money to burn
 */
 function burnFrom(address _from, uint256 _value) public returns (bool success) {
 require(balanceOf[_from] >= _value); // Check if the targeted balance is enough
 require(_value <= allowance[_from][msg.sender]); // Check allowance
 balanceOf[_from] -= _value; // Subtract from the targeted balance
 allowance[_from][msg.sender] -= _value; // Subtract from the sender's allowance
 totalSupply -= _value; // Update totalSupply
 emit Burn(_from, _value);
 return true;
 }
}