#include <iostream>
#include <vector>
using namespace std;

int n;
int k = 0;

int string_sum(string s) {
  int ans = 0;
  for (char c: s) ans += c - '0';
  return ans;
}

void rec(int x, string s) {
  if (x == n - 1) {
    k++;
    return;
  }
  for (int i = 0; i < x + 2 - string_sum(s); i++)
    rec(x + 1, s + char(48 + i));
}

int main() {
  cin >> n;
  rec(0, "");
  cout << k << '\n';
}