<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<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 2e6 + 5;
const ll mod = 1e9 + 7;
string s;
ll x;
int main() {
    ios_base::sync_with_stdio(false);
    cin >> x;
    cout << 2 - x * x << "\n";
    return 0;
}