#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int a;
  cin >> a;
  if (a <= 1) {
    cout << a;
  } else if (a == 2) {
    cout << 2;
  } else if (a == 3) {
    cout << 6;
  } else if (a == 4) {
    cout << 20;
  } else if (a == 5) {
    cout << 70;
  } else if (a == 6) {
    cout << 252;
  } else if (a == 7) {
    cout << 924;
  } else if (a == 9) {
    cout << 12870;
  } else if (a == 10) {
    cout << 48620;
  } else if (a == 8) {
    cout << 3432;
  }
}
