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 max=0;
    for(int i=0;i*i<=N;i++){
        max=i*i;
    }
    System.out.println(max);
    
    
    }
}