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){
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int rt = (int) Math.floor(Math.sqrt(N));
    int ans = 0;
    int i = Math.max(0,rt-1);
    while(i*i<=N){
      ans = i*i;
      i++;
    }
    
    System.out.println(ans);
  }   
}