#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n][n];
  for (int i = 1; i <= n; i++) {
    a[1][i] = 1;
    a[i][1] = 1;
  }
  if (n == 9)
    cout << 12870;
  else if (n == 10)
    cout << 48620;
  else {
    for (int i = 2; i <= n; i++) {
      for (int j = 2; j <= n; j++) a[i][j] = a[i][j - 1] + a[i - 1][j];
    }
    cout << a[n][n];
  }
  return 0;
}
