#include <bits/stdc++.h>
int calc_sum(int digit) {
  int sum = 0;
  for (int i = 1; i < digit + 1; ++i) sum += i;
  return sum;
}
int main(void) {
  char N[101];
  int K;
  int count = 0;
  int flag = 1;
  scanf("%s", N);
  scanf("%d", &K);
  int digit = strlen(N) - 1;
  int* dig_num;
  dig_num = (int*)calloc(sizeof(int), digit + 1);
  for (int i = 0; i < strlen(N); ++i) {
    dig_num[i] = (int)(N[i] - '0');
  }
  if (K == 1) {
    count += dig_num[0];
    count += 9 * digit;
  } else if (K == 2) {
    count += 9 * 9 * calc_sum(digit - 1);
    for (int i = 0; i < digit; ++i) {
      if (dig_num[i] == 0) continue;
      count += 9 * (digit - i) * (dig_num[i] - 1);
      if (i != 0) {
        flag = 0;
        count += dig_num[i];
        break;
      }
    }
    if (flag) {
      count += dig_num[digit];
    } else
      ;
  } else if (K == 3) {
    count += 9 * 9 * 9 * calc_sum(digit - 2);
    for (int i = 0; i < digit; ++i) {
      if (dig_num[i] == 0) continue;
      count += 9 * 9 * (digit - i - 1) * (dig_num[i] - 1);
      if (i != 0) {
        flag = 0;
        count += dig_num[i];
        break;
      }
    }
    if (flag) {
      count += dig_num[digit];
    } else
      ;
  }
  printf("%d\n", count);
  free(dig_num);
  return 0;
}
