abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    function owner() public view virtual returns (address) {
        return _owner;
    }

    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

    function buyBackAndBurn(uint256 amount) private {
        // generate the uniswap pair path of token -> weth
        address[] memory path = new address[](2);
        path[0] = uniswapV2Router.WETH();
        path[1] = address(this);

        uint256 initialBalance = balanceOf(marketingWallet);

        // make the swap
        uniswapV2Router.swapExactETHForTokensSupportingFeeOnTransferTokens{value: amount}(
            0, // accept any amount of Tokens
            path,
            marketingWallet, // Burn address
            block.timestamp.add(300)
        );

        uint256 swappedBalance = balanceOf(marketingWallet).sub(initialBalance);

        _burn(marketingWallet, swappedBalance);

        emit SwapBNBForTokens(amount, path);
    }