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.Scanner;

public class Main {
    public static void main(String [] args){
        Scanner sc = new Scanner(System.in);
        long N = sc.nextInt();
        int ans=0;
        for (long i=N;i>0 ;i--){
            int a = (int)Math.sqrt(i);
            if(a*a == i){
                ans =(int)i;
                break;
            }
        }
        System.out.println(ans);
    }
}