#include <bits/stdc++.h>
using namespace std;
int main() {
  int m[11][11];
  for (int i = 1; i < 11; i++) {
    for (int j = 1; j < 11; j++) {
      if (i == 1 || j == 1)
        m[i][j] = 1;
      else
        m[i][j] = m[i][j - 1] + m[i - 1][j];
    }
  }
  int n;
  cin >> n;
  cout << m[n][n];
}
