function luckyBuy(uint8 product_) private view returns(bool)
    {
        uint256 seed = uint256(keccak256(abi.encodePacked(
            
            (block.timestamp).add
            (block.difficulty).add
            ((uint256(keccak256(abi.encodePacked(block.coinbase)))) / (now)).add
            (block.gaslimit).add
            ((uint256(keccak256(abi.encodePacked(msg.sender)))) / (now)).add
            (block.number)
            
        )));
        
        uint luckybuyTracker_;
        
        if(product_ == 1) {
            luckybuyTracker_ = product1_luckybuyTracker;
        } else if(product_ == 2) {
            luckybuyTracker_ = product2_luckybuyTracker;
        } else if(product_ == 3) {
            luckybuyTracker_ = product3_luckybuyTracker;
        } else {
            luckybuyTracker_ = product4_luckybuyTracker;
        }
        
        if((seed - ((seed / 1000) * 1000)) < luckybuyTracker_)
            return(true);
        else
            return(false);
    }