<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;
#define fastio ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define ll long long 
#define  pll pair<ll,ll>
#define  vll vector<ll>
#define vs vector<string>
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
#define pb push_back
#define ppb pop_back
# define ln cout << "\n" ;
#define maxHeap priority_queue<ll>
#define minHeap priority_queue <ll, vector<ll>, greater<ll> > 
#define MOD 1000000009
#define MAX 2000000000000000000
#define MAXN 1000006
#define yes "YES"
#define no "NO"


int main() 
{
	fastio
	ll n, ans;
	cin >> n;
	ans = 2-(n*n);
	cout << ans; ln;
	return 0;
}