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 iline = sc.nextInt();
		int reti = 0;
        for(int i=1;;i++){
        	if(iline<i*i){
        		break;
        	}
        	reti++;
        }
        
		System.out.println(reti*reti);
    }
}
