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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
    using namespace std;
    
    int main() {
        int x;
        cin>>x;
        int ans=0;
      if(x==1){cout<<1<<endl;}
      else{
        for(int i=2;i<33;i++){
            int A=i;
            while(A<=x){
                A*=i;
                if(A<=x){
                    ans = max(ans, A);
                }

            }
        }
       
        
        
        cout<<ans<<endl;
      }
    }