#include <bits/stdc++.h>
using namespace std;

template <typename A, typename B>
string to_string(pair<A, B> p);
 
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);
 
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);
 
string to_string(const string& s) {
  return '"' + s + '"';
}

string to_string(const char& ch) {
	string s = "";
	s += ch;
	return "'" + s + "', ";
}
 
string to_string(const char* s) {
  return to_string((string) s);
}
 
string to_string(bool b) {
  return (b ? "true" : "false");
}
 
string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}
 
template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}
 
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
 
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
 
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}
 
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
 
void debug_out() { cout << endl; }
 
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cout << " " << to_string(H);
  debug_out(T...);
}
 
#ifdef LOCAL_DEFINE
#define debug(...) cout << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
   
#define int long long
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(),(v).end()
typedef pair<int, int> pii;
const int mod = (int) 1000000007; // 998244353;
const int inf = (int) 2e18;

vector<int> num;
int dp[210][10][5];

int solve(int ind, int lft, int edge)
{
	if(lft < 0) return 0;
	if(ind == sz(num))
		return (lft == 0 ? 1 : 0);
	if(dp[ind][lft][edge] != - 1)
		return dp[ind][lft][edge];
	int lim = (edge ? num[ind] : 9);
	int res = 0;
	for(int i = 0; i <= lim; ++ i)
	{
		int new_edge = (edge && i == lim ? 1 : 0);
		if(i != 0)
			res += solve(ind + 1, lft - 1, new_edge);
		else
			res += solve(ind + 1, lft, new_edge);
	}
	return dp[ind][lft][edge] = res;
}

int func(string s, int k)
{
	num.clear();
	for(int i = 0; i < sz(s); ++ i)
		num.push_back(s[i] - '0');
	memset(dp, -1, sizeof(dp));
	return solve(0, k, 1);
}

int32_t main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout << fixed << setprecision(9);
	#ifdef LOCAL_DEFINE
		freopen("in.txt", "rt", stdin);
	#endif
	
	string s;
	cin >> s;
	int k;
	cin >> k;
	cout << func(s, k) - func("0", k) << '\n';
	
	return 0;
}






Measured memory_bytes: 3764