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;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		
		for(long i = 1; i <= N; i++) {
			if(i * i > N) {
				System.out.println((i - 1) * (i - 1));
				break;
			} else if(i * i == N) {
				System.out.println(i * i);
				break;
			}
		}
	}
}
