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 max = 0;
		int x = scan.nextInt();

		for(int i = 1; i <= x; i++){
			int abs = 0;
			for(int j = 2; j <= x; j++){

				abs =(int) Math.pow((double)i, (double)j);

				if(abs > x){
					break;
				}
				if(abs > max){
					max = abs;
				}
			}
		}
		System.out.println(max);
	}
}