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.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();//, n = sc.nextInt();
		int sum=0,count=1,flag=0,max=-999999,min=99999;
		//String[] array = new String[n];
		//String s=sc.next();//,t=sc.next();
		String buff1,buff2;
		while(sum<n) {
			sum=count*count;
			if(sum>n) {
				sum=(count-1)*(count-1);
				break;
			}
			count++;
		}

		System.out.println(sum);

	}
	public static int sample(int n) {
		return n;
	}

}