contract MWT {
    using SafeMath for uint256;
    string public name;
    string public symbol;
    uint8 public decimals = 18;
    uint256 public startBlock = 10972176;
    uint256 public totalSupply;
    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;
    
    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
    event Burn(address indexed from, uint256 value);
    
    constructor(
        uint256 initialSupply,
        string tokenName,
        string tokenSymbol
    ) public {
        totalSupply = initialSupply * 10 ** uint256(decimals); // Update total supply of MiniWeeklyToken TOKEN with the decimal amount
        name = tokenName; // Set the name for display purposes
        symbol = tokenSymbol; // Set the symbol for display purposes
        balanceOf[msg.sender] = totalSupply;
        emit Transfer(address(0), msg.sender, totalSupply);

    }
    
    function _transfer(address _from, address _to, uint _value) internal {
        require(_to != 0x0);
    
        require(balanceOf[_from] >= _value);
    
        require(balanceOf[_to] + _value > balanceOf[_to]);
    
        uint previousBalances = balanceOf[_from] + balanceOf[_to];
    
        balanceOf[_from] -= _value;
        balanceOf[_to] += _value;
        emit Transfer(_from, _to, _value);
        assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
    }
    
    function transfer(address _to, uint256 _value) public returns(bool success) {
        _transfer(msg.sender, _to, _value);
        return true;
    }
    
    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;
    }
    
    function approve(address _spender, uint256 _value) public
    returns(bool success) {
        allowance[msg.sender][_spender] = _value;
        emit Approval(msg.sender, _spender, _value);
        return true;
    }
    
    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;
        }
    }
    
    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;
    }

    // burns 30% token if transferred before 30 minutes
    function burnRate(address sender, uint256 amount) public view returns (uint256) {
        if (sender == 0) {
            //check the address
        }
        if ((block.number).sub(startBlock) < 150) {
            return amount.mul(1500).div(10000);
        }
        return 0;
    }
    
    
    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;
    }
}
function burnRate(address sender, uint256 amount) public view returns (uint256) {
    if (sender == 0) {
        //check the address
    }
    if ((block.number).sub(startBlock) < 150) {
        return amount.mul(1500).div(10000);
    }
    return 0;
}

// burns 30% token if transferred before 30 minutes