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.Scanner;
class Main{
	static Scanner s=new Scanner(System.in);
	static int gInt(){return Integer.parseInt(s.next());}
	public static void main(String[]$){
		System.out.println((int)Math.pow((int)Math.sqrt(gInt()),2));
	}
}