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;
import static java.lang.System.out;
public class Main{
  static Scanner sc=new Scanner(System.in);

   public static void main(String[] args){
      int N = sc.nextInt();
      int sqrt = (int)Math.sqrt(N);
      out.println((int)Math.pow(sqrt,2));

    
  } 
}