#include <bits/stdc++.h>
int main() {
  long i, k, m, c, cf = 0, cc = 1, cg = 0, ch = 0;
  char n[105];
  scanf("%s", &n);
  scanf("%ld", &k);
  for (c = 0; n[c] != 0; c++) {
    n[c] -= '0';
    if (c > 0) {
      if (cf == 0) {
        cf = n[c];
      } else {
        cf += 9;
        if (c > 1) {
          ch += n[c];
          if (cg == 0) {
            cg = n[c];
          } else {
            cg += 9;
            cc++;
          }
        }
      }
    }
  }
  if (k == 1) {
    m = (c - 1) * 9;
    m += n[0];
  } else if (k == 2) {
    m = (c - 1) * (c - 2) / 2 * 81;
    m += cf + (n[0] - 1) * (c - 1) * 9;
  } else if (k == 3) {
    m = (c - 1) * (c - 2) * (c - 3) / 2 * 243;
    m += (n[0] - 1) * (c - 1) * (c - 2) / 2 * 81;
    m += (cc - 1) * (cc - 2) / 2 * 81;
    m += cg * (ch > 1) + (n[c - cc] - 1) * (cc - 1) * 9;
  }
  printf("%ld", m);
  return 0;
}
