Problem:
Score : 200 points

Problem Statement

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.

Constraints

1 ≤ X ≤ 1000

X is an integer.

Input

Input is given from Standard Input in the following format:

X

Output

Print the largest perfect power that is at most X.

Sample Input 1

10

Sample Output 1

9

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

Sample Input 2

1

Sample Output 2

1

Sample Input 3

999

Sample Output 3

961

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;
class Main
{
    public static void main(String[] args)
    {
        Scanner scan = new Scanner(System.in);
        int x = scan.nextInt();
        int num = 1;

        for(int i = 10; i > 1; i--)
        {
            for(int j = 2; j < 40; j++)
            {
                double tmp = Math.pow(j,i);
                if(tmp <= x) num = (int) tmp;
            }
        }
        System.out.print(num);
        scan.close();
    }
}