#include<cstdio> #include<cstdlib> #include<cstring> #include<cmath> //#include<cctype> #include<climits> #include<iostream> #include<string> #include<vector> #include<map> //#include<list> #include<queue> #include<deque> #include<algorithm> //#include<numeric> #include<utility> #include<complex> //#include<memory> #include<functional> #include<cassert> #include<set> #include<stack> const int dx[] = {1, 0, -1, 0}; const int dy[] = {0, 1, 0, -1}; using namespace std; typedef long long ll; typedef vector<int> vi; typedef vector<ll> vll; typedef pair<int, int> pii; int main() { cin.tie(0); ios::sync_with_stdio(false); ll N; cin >> N; ll g = N*(N-1) / 2; cout << __gcd(g, N) << endl; return 0; }