#include <bits/stdc++.h>
using namespace std;
template <typename A, typename B>
string to_string(pair<A, B> p);
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);
string to_string(const string& s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string((string)s); }
string to_string(bool b) { return (b ? "true" : "false"); }
string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}
template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto& x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
void debug_out() { cout << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cout << " " << to_string(H);
  debug_out(T...);
}
void init() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  freopen(
      "e"
      ".inp",
      "r", stdin);
  freopen(
      "e"
      ".out",
      "w", stdout);
}
int n;
long long dp[105][3][5];
string a;
long long cal(int pos, int ok, int j) {
  if (j == 0) {
    return 1;
  }
  if (pos == n + 1) return 0;
  long long& res = dp[pos][ok][j];
  if (res != -1) return res;
  res = 0;
  int low = 0, high = 9;
  if (ok) high = a[pos] - '0';
  for (int i = low; i <= high; i++) {
    int new_ok = 0;
    if (ok && i == high) new_ok = 1;
    if (i == 0)
      res += cal(pos + 1, new_ok, j);
    else if (j - 1 >= 0)
      res += cal(pos + 1, new_ok, j - 1);
  }
  return res;
}
int main() {
  cin >> a;
  int k;
  cin >> k;
  a = " " + a;
  memset(dp, -1, sizeof(dp));
  n = a.length() - 1;
  cout << cal(1, 0, k);
}
