#include <bits/stdc++.h>
using namespace std;
int main(){
	int i;
	cin>>i;
	cout<<(i<0?i-1:(i==0?0:i+1));
	return 0;
}

/**************************************************************
	Problem: 1038
	User: zhouhongyi
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/