原文：

Your answer is considered correct, if each of your answers has absolute or relative error not greater than $10^{-6}$.

Formally, let your answer be $a$ , and the jury's answer be $a$. Your answer is considered correct if $\dfrac{|a-b|}{\max(1,|b|)}\le 10^{-6}$.

翻译：

输出这个最大值，保留十位小数。

这题开了 SPJ，误差不超过 $10^{-6}$ 不就可以吗？为什么一定要保留 $10$ 位？