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.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int ans = 0;
    
    for(int i = 1; i*i <= n; ++i){
      int num = (int)Math.pow(i,2);
      if(num <= n){
        ans = (int)num;
      }else{
        break;
      }
      
    }
    
    System.out.print(ans);
    
  }
}