<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 <cstdlib>
#include <cmath>
#include <limits.h>
#include <vector>
#include <algorithm>
#include <cstdlib>
#include <string>
#include <cstddef>
#include <unordered_set>
#include <unordered_map>
#include <map>
#include <queue>
#include <set>
#include <string.h>
#include <utility>

#define FastIO                    \
	ios_base::sync_with_stdio(0); \
	cin.tie(0);                   \
	cout.tie(0);

using ll = long long;
using namespace std;

int main()
{
	FastIO;

	int n;
	cin >> n;
	cout << (2 - n * n); // got the formula from braille
}