<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 <algorithm>
#include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <stack>
#include <tuple>

using namespace std;

typedef long long ll;

int main() {
	int a;
	cin >> a;
	cout << 2 - a * a;
}	
/*

*/