<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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class F {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		FastScanner fs = new FastScanner();
		int a = fs.nextInt();
		System.out.println(2-a*a);

	}
	static class FastScanner{
		BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer s = new StringTokenizer("");
		public String next() {
			while(!s.hasMoreElements()) {
				try {
					s = new StringTokenizer(bf.readLine());
					
				}catch(IOException e) {
					e.printStackTrace();
					
				}
				
			}
			return s.nextToken();
		}
		public int nextInt() {
			return Integer.parseInt(next());
		}
		public int[] readArray(int n) {
			int[] a = new int[n];
			for(int i = 0; i < a.length; i++) a[i] = nextInt();
			return a;
		}
		public long nextLong() {
			return Long.parseLong(next());
		}
		
	}


}
