#include <bits/stdc++.h> #include <atcoder/all> using namespace std; using namespace atcoder; #define ll long long #define rep(i, n) for (int i = 0; i < (n); i++) #define coutf(f) cout << fixed << setprecision(f) #define all(v) (v).begin(), (v).end() #define rall(v) (v).rbegin(), (v).rend() int main() { int n; cin >> n; ll ans = 1; rep(i, n) { ans *= 2 * n - i; ans /= i + 1; } ans /= n + 1; cout << ans << endl; return 0; }