/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone {
	public static void main (String[] args) {
		Scanner x = new Scanner(System.in);
		int a = x.nextInt();
		int y;
		if( a>0 )   y = -a*a;
		else    y = -a;
		System.out.print(y);
	}
}