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){
    
    Scanner sc = new Scanner(System.in);
    long N = sc.nextInt();
 
    long cou = 0;
    for(long i=1; i<=N; i++){
       if(i*i<=N) {
    	   cou++;
       }
}
 	System.out.println(cou*cou);
    }
}
