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) throws Exception {
    Scanner scanner = new Scanner(System.in);
    try {
      int N = scanner.nextInt();
      int ans = 0;
      for (int i = 0; i * i <= N; i++) {
        ans = i * i;
      }
      System.out.println(ans);
    }
    finally {
      scanner.close();
    }
  }
}