<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 <set>
#include <cmath>
#include <string>
#include <queue>
using namespace std;
typedef long long ll;
int main()
{
	int n;
	cin >> n;
	cout << 2 - n * n;
}