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[]) {
        try (Scanner in = new Scanner(System.in)) {
            int N = in.nextInt();

            int max = 0;
            for (int i = 1; i * i <= N; i++) {
                max = i * i;
            }

            System.out.println(max);
        }
    }
}
