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>=1;i--){
      if(Math.sqrt(i)%1==0){
        System.out.println(i);
        break;
      }
    }


	}
}
