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 in = new Scanner(System.in);

      int N = in.nextInt();
      int A = 1;
      int ANS = 0;

      while(A * A <= N) {
          ANS = A * A;
          A++;
      }

      System.out.println(ANS);


    }
}