<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
//https://codeforces.com/contest/1505/problem/F
//F. Math
import java.util.*;
import java.io.*;
public class CF_1505_F{
	public static void main(String[] args) throws Exception{
		
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));
		
		int a = Integer.parseInt(br.readLine());

		pw.print(2-a*a);
		pw.flush();
		pw.close();
	}
}