<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 <iostream>
#include <vector>
#include <algorithm>

int main(void)
{
    std::cin.tie(0);
    std::ios_base::sync_with_stdio(false);

    int a;
    std::cin >> a;

    std::cout << 2-a*a << "\n";

    return 0;
}