<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
#include <cstdio>
int a, b;
int main () {
    scanf ("%d", &a);
    printf ("%d\n", 2 - a*a);
}