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 N = sc.nextInt();
       
       int max =  Integer.MIN_VALUE;
               
       for(int i = 1 ;i*i <=N;i++){
           max = Math.max(i*i,max);
       }

       System.out.println(max);
      
       
       
       
   }
}
        