#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)

typedef long long ll;
ll gcd(ll a, ll b) { return a ? gcd(b%a, a) : b; }

int main()
{
	ll N; cin >> N;

	cout << gcd(N, (N * (N-1) / 2LL)) << endl;
}