#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
#define rep(i, n) for(int i = 0; i < (n); i++)
int dp[110][4][2];

int main() {
  string s; cin >> s;
  int n = s.size();
  int K; cin >> K;
  dp[0][0][0] = 1;
  rep(i, n) rep(j, 4) rep(k, 2) {
    int nd = s[i] - '0';
    rep(d, 10) {
      int ni = i + 1, nj = j, nk = k;
      if(d != 0) nj++;
      if(nj > K) continue;
      if(k == 0) {
        if(d > nd) continue;
        if(d < nd) nk = 1;
      }
      dp[ni][nj][nk] += dp[i][j][k];
    }
  }
  int ans = dp[n][K][0] + dp[n][K][1];
  cout << ans << endl;
  return 0;
}
