Contest: Task: Related: TaskA TaskC

Score : $200$ points

You are given a positive integer $X$.
Find the largest *perfect power* that is at most $X$.
Here, a perfect power is an integer that can be represented as $b^p$, where $b$ is an integer not less than $1$ and $p$ is an integer not less than $2$.

- $1$ $≤$ $X$ $≤$ $1000$
- $X$ is an integer.

Input is given from Standard Input in the following format:

$X$

Print the largest perfect power that is at most $X$.

10

9

There are four perfect powers that are at most $10$: $1$, $4$, $8$ and $9$. We should print the largest among them, $9$.

1

1

999

961