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);
    	int N = sc.nextInt();
    	int ans =0;
    	
    	for(int i =1; i*i<=N; i++){
    	    ans = i*i;
    	}
    	
    	System.out.println(ans);
        
 	}
}