#include <bits/stdc++.h>
#pragma GCC optimize("O3")
long mod(long a) {
  long long c = a % (long long)(1e9 + 7);
  if (c >= 0) return c;
  return c + (long long)(1e9 + 7);
}
long long po(long a, long b) {
  if (b == 0) {
    return 1;
  }
  long long z = po(a, b / 2);
  z = mod(z * z);
  if (b % 2 != 0) {
    z = mod(a * z);
  }
  return z;
}
bool prime_(int n) {
  if (n == 1) {
    return false;
  } else if (n == 2) {
    return true;
  } else {
    for (int i = 2; i <= std::sqrt(n); i++) {
      if (n % i == 0) {
        return false;
      }
    }
    return true;
  }
}
long long gcd_(long long a, long long b) {
  if (a < b) {
    std::swap(a, b);
  }
  if (a % b == 0) {
    return b;
  } else {
    return gcd_(b, a % b);
  }
}
long long lcm_(long long x, long long y) { return (x / gcd_(x, y)) * y; }
int main() {
  using namespace std;
  string s;
  cin >> s;
  int k;
  cin >> k;
  int t = s[0] - '0';
  int n = s.size();
  int ans = 0;
  if (k == 1) {
    ans = 9 * (n - 1) + t;
    cout << ans << endl;
    return 0;
  }
  if (k == 2) {
    int index = -1;
    int t2;
    for (int i = 0; i < n; i++) {
      if (i == 0) continue;
      if (s[i] == '0') continue;
      index = i;
      t2 = s[i] - '0';
      break;
    }
    ans = ((n - 1) * (n - 2) / 2) * 9 * 9 + (t - 1) * (n - 1) * 9;
    if (index == -1) {
      cout << ans << endl;
      return 0;
    }
    ans += t2 + 9 * (n - (index + 1));
    cout << ans << endl;
    return 0;
  }
  if (k == 3) {
    ans = ((n - 1) * (n - 2) * (n - 3) / 6) * 9 * 9 * 9 +
          (t - 1) * ((n - 1) * (n - 2) / 2) * 9 * 9;
    int index = -1;
    int t2;
    for (int i = 0; i < n; i++) {
      if (i == 0) continue;
      if (s[i] == '0') continue;
      index = i;
      t2 = s[i] - '0';
      break;
    }
    if (index == -1) {
      cout << ans << endl;
      return 0;
    }
    ans += (t2 - 1) * (n - (index + 1)) * 9;
    int index2 = -1;
    int t3;
    for (int i = index + 1; i < n; i++) {
      if (s[i] == '0') continue;
      index2 = i;
      t3 = s[i] - '0';
      break;
    }
    if (index2 == -1) {
      cout << ans << endl;
      return 0;
    }
    ans += t3 + 9 * (n - (index2 + 1));
    cout << ans << endl;
  }
  return 0;
}
