#include <bits/stdc++.h>
using namespace std;
const int MAX = 510000;
const int MOD = 1000000007;
long long fac[MAX], finv[MAX], inv[MAX];
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}
long long COM(int n, int k) {
  if (n < k) return 0;
  if (n < 0 || k < 0) return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
int main() {
  string N;
  int K;
  long long ans = 0;
  cin >> N;
  cin >> K;
  if (N.size() < 6) {
    long long int n = stoi(N);
    for (int i = 0; i <= n; i++) {
      int no = 0;
      string now = to_string(i);
      for (int j = 0; j < now.size(); j++) {
        if (now[j] != '0') {
          no++;
        }
      }
      if (no == K) {
        ans++;
      }
    }
    cout << ans << endl;
    return 0;
  }
  COMinit();
  for (int i = K; i < N.size(); i++) {
    ans += pow(9, K) * COM(i - 1, K - 1);
  }
  if (K == 1) {
    ans += N[0] - '0';
  } else if (K == 2) {
    ans += (N[0] - '0') * 9 * COM(N.size() - 2, K - 1);
    ans += (N[0] - '0' - 1) * 9 + (N[1] - '0');
  } else {
    ans += (N[0] - '0') * pow(9, 2) * COM(N.size() - 2, 2);
    ans += ((N[0] - '0' - 1) * 9 + (N[1] - '0')) * 9 * COM(N.size() - 3, K - 2);
    ans += ((N[0] - '0' - 1) * 9 + (N[1] - '0') - 1) * 9 + (N[2] - '0');
  }
  cout << ans << endl;
}
