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);
      long n=sc.nextLong();
      for(long i=n; i>0L; i--){
        double sqrtOf=Math.sqrt(i);
        if(sqrtOf==Math.floor(sqrtOf)){
        	System.out.println(i);
            return;
        }
      }
    }
}