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 target = 0;
		for (int i = n; 1 <= i; i--) {
			target = (int) Math.sqrt(i);
			if (i == Math.pow(target, 2)) {
				target = i;
				break;
			}
		}

		System.out.println(target);

	}

}
