<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>
using namespace std;
int main()
{
    int n;cin>>n;
    cout<<2-n*n;
}