# Wanting to understand what these numbers mean

Can someone please let me know if these numbers are correct? I'm starting with 1 quadrillion tokens. I will have a 3% buyback fee, 3% marketing fee, 3% redistribution fee, and 1% dev fee. I can post the full code if that will help. Any help is greatly appreciated.

``````  uint256 private constant MAX = ~uint256(0);
uint256 private _tTotal = 1000000000 * 10**6 * 10**9;
uint256 private _rTotal = (MAX - (MAX % _tTotal));
uint256 private _tFeeTotal;
``````
``````  uint256 public _maxTxAmount = 1000000 * 10**6 * 10**9;
uint256 private minimumTokensBeforeSwap = 200000 * 10**6 * 10**9;
uint256 private buyBackUpperLimit = 1 * 10**18;
``````
``````   uint256 contractTokenBalance = balanceOf(address(this));
bool overMinimumTokenBalance = contractTokenBalance >= minimumTokensBeforeSwap;

if (!inSwapAndLiquify && swapAndLiquifyEnabled && to == uniswapV2Pair) {
if (overMinimumTokenBalance) {
contractTokenBalance = minimumTokensBeforeSwap;
swapTokens(contractTokenBalance);
}
if (buyBackEnabled && balance > uint256(1 * 10**18)) {

}
}

``````
``````
function afterPreSale() external onlyOwner {
setSwapAndLiquifyEnabled(true);
_taxFee = 3;
_liquidityFee = 6;
_devFee = 1;
_maxTxAmount = 1000000 * 10**6 * 10**9;
}

``````

Just curious about if you have a `presale` function built in the contract. What does it look like?

I'm not entirely sure on how that works but i can show you the code i'm using.