uniswap safe input amount is showed here to anti sandwitch attack.
essentially the safe input amount is 0.30135474% of amount of input token in the pool because of the transaction fee is 0.3%.
thus, the 0.3% transaction fee in uniswap provide benefits not only for the liquidity providers but also for the traders.
according to the expression show here the safe input amout is about transaction fee ✕ amount of input token in the pool when transaction fee is small enough (less than 1%).