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 a = sc.nextInt();
		int i = 0;
		while(i*i <= a){
			i++;
			
		}
		System.out.println((i-1)*(i-1));
	}
}