#include <bits/stdc++.h>
int main() {
  long i, k, m, c, cf = 0, cm = 0, cc = 0, ci = 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 (ci == 0) ci = c - 1;
        if (cc == 0) {
          cc = n[c];
        } else {
          cc += 9;
        }
      }
    }
  }
  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;
    for (; ci < c; ci++) {
      if (cm == 0) {
        m += n[ci] * cc;
        cc -= n[ci];
        if (n[ci] != 0) cm = 1;
      } else {
        m += 9 * cc;
        cc -= 9;
      }
    }
  }
  printf("%ld", m);
  return 0;
}
