Find the largest square number not exceeding N. Here, a square number is an integer that can be represented as the square of an integer.

Constraints

* 1 \leq N \leq 10^9
* N is an integer.

Input

Input is given from Standard Input in the following format:


N


Output

Print the largest square number not exceeding N.

Examples

Input

10


Output

9


Input

81


Output

81


Input

271828182


Output

271821169
import java.util.*;
 
public class Main {
 
    static Scanner in = new Scanner(System.in);
    void solve() {
        int n = in.nextInt();
        for(int i = 40000; i > 1; i--){
            if(i * i <= n){
                System.out.println(i * i);
                return;
            }
        }
        System.out.println(1);
    }
 
    public static void main(String[] args) {
        new Main().solve();
    }
}