#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  vector<int> v;
  while (cin.peek() != '\n') v.push_back(getchar());
  int n = (int)v.size();
  int k;
  cin >> k;
  ll dp1[101][5] = {};
  ll dp2[101][5] = {};
  dp1[0][1] = v[0] - 1;
  dp1[0][0] = 1;
  dp2[0][0] = 1;
  for (int i = 0; i < n - 1; ++i) {
    for (int j = 0; j <= k; ++j) {
      dp1[i + 1][j] += dp1[i][j] + dp2[i][j] * (v[i + 1] != 0);
      dp1[i + 1][j + 1] += dp1[i][j] * 9 + dp2[i][j] * max<ll>(v[i + 1] - 1, 0);
      dp2[i + 1][j] += dp2[i][j] * (v[i + 1] == 0);
      dp2[i + 1][j + 1] += dp2[i][j] * (v[i + 1] != 0);
    }
  }
  cout << dp1[n - 1][k] + dp2[n - 1][k] << endl;
}
