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.*;
import java.math.BigInteger;
class Main{

     public static void main(String []args){
      Scanner scan = new Scanner(System.in);
      int n = scan.nextInt() ;
        for(int i = n ; i>=0 ; i--){
            if(Math.sqrt(i) - (int)Math.sqrt(i) == 0 ){
                System.out.println(i);break;
            }
        }
      }
}