#include <algorithm>
#include <vector>
#include <cfloat>
#include <string>
#include <cmath>
#include <set>
#include <cstdlib>
#include <map>
#include <ctime>
#include <iomanip>
#include <functional>
#include <deque>
#include <iostream>
#include <cstring>
#include <queue>
#include <cstdio>
#include <stack>
#include <climits>
#include <sys/time.h>
#include <cctype>

using namespace std;

typedef long long ll;

ll gcd(ll x, ll y) { 
  return y == 0 ? x : gcd(y, x % y); 
}

int main() {
  ll n;
  scanf("%lld", &n);
  printf("%lld\n", gcd(n, n*(n-1)/2));
}