<image> <image>

*The two images are equivalent, feel free to use either one.

Input

The input contains a single integer a (-100 ≤ a ≤ 100).

Output

Output the result – an integer number.

Example

Input


1


Output


1
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
	Scanner scanner = new Scanner(System.in);
	int ans = scanner.nextInt();
	System.out.println(2-ans*ans);
    }
}