#include <bits/stdc++.h>
long Combination(long n, long r) {
  long answer = 1;
  if (n - r < r) {
    r = n - r;
  }
  for (long i = 1; i <= r; i++) {
    answer *= n + 1 - i;
    answer /= i;
  }
  return answer;
}
int main(void) {
  char n[200];
  scanf("%s", n);
  int length = strlen(n);
  int k;
  scanf("%d", &k);
  long count;
  long sum = 0;
  int flag;
  for (int digits = k; digits < length; digits++) {
    count = pow(9, k);
    count *= Combination(digits - 1, k - 1);
    sum += count;
  }
  if (k == 1) {
    sum += n[0] - '0';
  } else if (k == 2) {
    sum += (n[0] - '0' - 1) * 9 * (length - 1);
    flag = 0;
    for (int i = 1; i < length; i++) {
      if (flag == 0) {
        sum += n[i] - '0';
      } else {
        sum += 9;
      }
      if (n[i] != '0') {
        flag = 1;
      }
    }
  } else {
    sum += (n[0] - '0' - 1) * pow(9, 2) * Combination(length - 1, 2);
    for (int second = 1; second < length - 1; second++) {
      if (n[second] != '0') {
        sum += (n[second] - '0' - 1) * 9 * (length - second - 1);
      }
    }
    for (int second = 1; second < length - 1; second++) {
      for (int third = second + 1; third < length; third++) {
        flag = 0;
        for (int i = 1; i < third; i++) {
          if (i == second) {
            continue;
          }
          if (n[i] != '0') {
            flag = 1;
            break;
          }
        }
        if (flag == 0) {
          sum += n[third] - '0';
        } else {
          sum += 9;
        }
      }
    }
  }
  printf("%ld\n", sum);
  return 0;
}
