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.*;

class Main{
  public static void main(String[] args)throws Exception{
    Scanner sc = new Scanner(System.in);
    
    int n = sc.nextInt();
    
    for(int i=n; i>0; i--){
      double ans = Math.sqrt(i);
      if((ans-(int)Math.sqrt(i))==0){
        System.out.println(i);
        break;
      }
    }
  }
}