<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.*;
import java.lang.*;
import java.io.*;

public class Main {
	public static void main (String[] args) throws Exception {
		//code
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

           int n=Integer.parseInt(br.readLine());
		System.out.println(2-n*n);
      }
	}

