<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
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,bmi,bmi2")
//#define _GLIBCXX_DEBUG
//#include <io.h>
//#include <fcntl.h>
#include <x86intrin.h>
#include <cstring>
#include <iostream>
#include <streambuf>
#include <bitset>
#include <locale>
#include <cstdio>
#include <atomic>
#include <vector>
#include <algorithm>
#include <cmath>
#include <complex>
#include <climits>
#include <random>
#include <set>
#include <list>
#include <map>
#include <unordered_map>
#include <deque>
#include <stack>
#include <queue>
#include <string>
#include <iomanip>
#include <unordered_set>
#include <thread>
#include <sstream>
//#pragma GCC target("tune=native")

int main()
{
	int a; std::cin >> a;
	printf("%d\n", 2-(a*a));
}
