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.*;

public class Main {
	static Scanner sc = new Scanner(System.in);
	
	public static void main(String[] args) {
		double N = sc.nextDouble();
		
		for (double i = N; i >= 0; i--) {
			double root = Math.sqrt(i);
			if (root % 1 == 0) {
				System.out.println((int)i);
				return;
			}
		}
		
	}
}
