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.nextLong();
		long ans_final=0;
		long ans=(int)Math.sqrt(N);
		if(ans*ans==N) ans_final=N;
		else ans_final=ans*ans;

		System.out.println(ans_final);
	} 
}