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 {
	public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	long N = sc.nextInt();
	for(long i = N;i >1;i--)
	{
		if(i*i <= N){
			System.out.println(i*i);
			break;
		}
	}
	if(N == 1 || N == 2 || N == 3){
		System.out.println(1);		
	}
	}
}
