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 intInput = sc.nextInt();

        int count = 1;
        while (count * count <= intInput){
            count ++;
        }
        count --;

        System.out.println(count * count);
    }
}