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
/* Filename: ABC077B.java
 * Author: Mushiyo
 */

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		
		while(input.hasNext()){
			int N = input.nextInt();
			int sqrtN = (int) Math.sqrt(N);
			
			System.out.println(sqrtN * sqrtN);
		}
	}

}
