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 scan=new Scanner(System.in);
        int N=scan.nextInt();
        int i;
        int ans=1;
        for(i=1;i<(int)Math.sqrt(N);i++){
        }
        ans=i*i;
        System.out.println(ans);

    }
}