#include <bits/stdc++.h>
using namespace std;
int dy4[4] = {-1, 0, +1, 0};
int dx4[4] = {0, +1, 0, -1};
int dy8[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
int dx8[8] = {0, 1, 1, 1, 0, -1, -1, -1};
const long long INF = 1LL << 60;
const long long MOD = 1e9 + 7;
bool greaterSecond(const pair<int, int>& f, const pair<int, int>& s) {
  return f.second > s.second;
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
long long nCr(long long n, long long r) {
  if (r == 0 || r == n) {
    return 1;
  } else if (r == 1) {
    return n;
  }
  return (nCr(n - 1, r) + nCr(n - 1, r - 1));
}
long long nPr(long long n, long long r) {
  r = n - r;
  long long ret = 1;
  for (long long i = n; i >= r + 1; i--) ret *= i;
  return ret;
}
string s;
int K;
long long dp[110][2][4] = {0};
int main(void) {
  cin >> s >> K;
  dp[0][0][0] = 1;
  for (int i = 0; i < s.size(); i++) {
    int now = s[i] - '0';
    for (int j = 0; j < 2; j++) {
      for (int k = 0; k < 3; k++) {
        for (int l = 0; l <= (j ? 9 : now); l++) {
          dp[i + 1][j || (l < now)][l == 0 ? k : k + 1] += dp[i][j][k];
        }
      }
    }
  }
  cout << dp[s.size()][0][K] + dp[s.size()][1][K] << endl;
}
