#include <bits/stdc++.h>
using namespace std;
template <typename t>
t in(t q) {
  cin >> q;
  return q;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "[";
  for (int i = 0; i < ((int)(v).size()); ++i) {
    os << v[i];
    if (i != ((int)(v).size()) - 1) os << ",";
  }
  os << "]";
  return os;
}
template <typename T, typename S>
ostream &operator<<(ostream &os, const map<T, S> &v) {
  for (auto it : v) os << "(" << it.first << ":" << it.second << ")";
  return os;
}
template <typename T, typename S>
ostream &operator<<(ostream &os, const pair<T, S> &v) {
  os << "(" << v.first << "," << v.second << ")";
  return os;
}
const long double PI = acosl(-1);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::steady_clock::now().time_since_epoch().count());
inline int rand(int l, int r) {
  return uniform_int_distribution<int>(l, r)(rng);
}
inline long long rand(long long l, long long r) {
  return uniform_int_distribution<long long>(l, r)(rng64);
}
using namespace std;
const int N = 200005, M = 1005;
const long long MOD = 1e9 + 7;
const int OO = 1e9;
int a[11][11];
void solve() {
  int n;
  cin >> n;
  for (int i = 0; i <= n; i++) {
    a[i][1] = 1;
    a[1][i] = 1;
  }
  for (int i = 2; i <= n; i++) {
    for (int j = 2; j <= n; j++) {
      a[i][j] = a[i - 1][j];
      a[i][j] += a[i][j - 1];
    }
  }
  cout << a[n][n] << '\n';
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  solve();
  cerr << "time taken : " << (float)clock() / CLOCKS_PER_SEC << " secs" << '\n';
}
