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 {
  int count = 0;
  public static void main(String[] args) {
    new Main().run();
  }
  void run(){
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    for(int i = 1; N >= (i * i); i++){
      count++;
    }
    System.out.println(count * count);
  }
}
