#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;
}
long long FINV(int n) {
  if (n < 0) return 0;
  return finv[n];
}
int main() {
  COMinit();
  string s;
  cin >> s;
  int k;
  cin >> k;
  int d = s.size();
  int a[d];
  for (int i = 0; i < (d); ++i) a[d - 1 - i] = s[i] - '0';
  if (k > d) {
    cout << 0 << endl;
    return 0;
  }
  int ans = 0;
  if (k == 1) {
    ans = 9 * (d - 1) + a[d - 1];
  }
  if (k == 2) {
    ans = a[d - 1] * 9 * (d - 1) - (9 - a[d - 2]) + 9 * 9 * COM(d - 1, 2);
  }
  if (k == 3) {
    ans = a[d - 1] * 9 * 9 * COM(d - 1, 2) + 9 * 9 * 9 * COM(d - 1, 3);
    ans -= (9 - a[d - 2]) * (d - 2) * 9 + (9 - a[d - 3]);
  }
  cout << ans << endl;
  return 0;
}
