#include <bits/stdc++.h>
using namespace std;
namespace mine {
long long qread() {
  long long ans = 0, f = 1;
  char c = getchar();
  while (c < '0' or c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while ('0' <= c and c <= '9') ans = ans * 10 + c - '0', c = getchar();
  return ans * f;
}
void write(long long num) {
  if (num < 0) putchar('-'), num = -num;
  if (num >= 10) write(num / 10);
  putchar('0' + num % 10);
}
void write1(long long num) {
  write(num);
  putchar(' ');
}
void write2(long long num) {
  write(num);
  putchar('\n');
}
template <typename T>
inline bool chmax(T &a, const T &b) {
  return a < b ? a = b, 1 : 0;
}
template <typename T>
inline bool chmin(T &a, const T &b) {
  return a > b ? a = b, 1 : 0;
}
long long gcd(long long x, long long y) { return y ? gcd(y, x % y) : x; }
bool IN(long long x, long long l, long long r) { return l <= x and x <= r; }
void gg1() {
  write2(-1);
  exit(0);
}
void gg2() {
  puts("NO");
  exit(0);
}
const double eps = 1e-8;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
int mm(const int x) { return x >= MOD ? x - MOD : x; }
template <typename T>
void add(T &x, const int &y) {
  x = (x + y >= MOD ? x + y - MOD : x + y);
}
long long qpower(long long x, long long e, int mod = MOD) {
  long long ans = 1;
  while (e) {
    if (e & 1) ans = ans * x % mod;
    x = x * x % mod;
    e >>= 1;
  }
  return ans;
}
long long invm(long long x) { return qpower(x, MOD - 2); }
const int N = 2e6 + 10;
char str[N];
long long C(int n, int m) {
  long long ret = 1;
  for (int i = (n - m + 1), I = (n); i <= I; i++) ret = ret * i;
  for (int i = (1), I = (m); i <= I; i++) ret /= i;
  return ret;
}
void main() {
  scanf("%s", str + 1);
  int n = strlen(str + 1);
  int k = qread();
  long long ans = 0;
  int cnt = 0;
  for (int i = (1), I = (n); i <= I; i++) {
    for (int j = (0), I = (str[i] - '0' - 1); j <= I; j++) {
      int c2 = cnt + (j != 0);
      if (c2 <= k) ans += C(n - i, k - c2) * qpower(9, k - c2);
    }
    cnt += (str[i] != '0');
  }
  cnt = 0;
  for (int i = (1), I = (n); i <= I; i++) cnt += (str[i] != '0');
  ans += cnt <= k;
  write(ans);
}
};  // namespace mine
signed main() {
  srand(time(0));
  mine::main();
  if (0) cerr << "Time: " << 1.0 * clock() / CLOCKS_PER_SEC << "s";
}
