#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)n; i++)
#define rep2(i, j, n) for (int i = (int)j; i < (int)n; i++)
using ll =long long int;

int main() {
  int N;
  cin >> N;
  vector<int> v;
  int n = N, m = 0;
  while (n > 0) {
    v.push_back(n % 10);
    n /= 10;
    m++;
  }
  set<ll> st;
  auto f = [&](vector<int> v, int m) {
    ll ret = 0;
    ll p = 1;
    rep(i, m) {
      ret += p * v[i];
      p *= 10;
    }
    return ret;
  };
  rep(i, m+1) {
    vector<int> u(m+1);
    rep(j, m) {
      if (j < i) u[j] = v[j];
      else       u[j+1] = v[j];
    }
    rep(j, 10) {
      u[i] = j;
      if (f(u, m+1) != N)
	st.insert(f(u, m+1));
    }
  }
  cout << st.size() << endl;
  return 0;
}