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);
        int N = sc.nextInt();
        double k;
        k = Math.sqrt(N);
        double sq = Math.floor(k);
        int ans = (int) Math.pow(sq, 2);
        System.out.println(ans);
    }
}
