#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector<long long>;
using sll = set<long long>;
template <typename T>
T gcd(T a, T b) {
  return b ? gcd(b, a % b) : a;
}
template <typename T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
template <typename T>
map<T, T> getPrimeFactor(T n) {
  map<T, T> res;
  for (T i = 2; i * i <= n; ++i) {
    while (n % i == 0) {
      res[i]++;
      n /= i;
    }
  }
  if (n != 1) res[n] = 1;
  return res;
}
template <typename T>
bool IsPrimeNumber(T num) {
  if (num <= 2)
    return true;
  else if (num % 2 == 0)
    return false;
  double sqrtNum = sqrt(num);
  for (int i = 3; i <= sqrtNum; i += 2) {
    if (num % i == 0) {
      return false;
    }
  }
  return true;
}
long long modinv(long long a, long long m) {
  long long b = m, u = 1, v = 0;
  while (b) {
    long long t = a / b;
    a -= t * b;
    swap(a, b);
    u -= t * v;
    swap(u, v);
  }
  u %= m;
  if (u < 0) u += m;
  return u;
}
ll b;
ll func(ll n, ll k) {
  ll ret = 0;
  ll a = pow(9, k);
  for (ll i = 1; i <= b - k; i++) {
    if (k == 1) {
      ret += a;
    } else {
      ret += i * a;
    }
  }
  return ret;
}
int main() {
  ll n, k, ans = 0;
  std::cin >> n >> k;
  ll n2 = n;
  b = 1;
  while (n2 >= 10) {
    n2 /= 10;
    b++;
  }
  ans = func(n, k);
  ll tmp10x = pow(10, b - 1);
  if (k == 1) {
    ans += n / tmp10x;
  } else if (n > tmp10x) {
    b--;
    while (tmp10x >= pow(10, k - 1)) {
      ll tmp = n / tmp10x;
      if (tmp >= 1) {
        ans += (tmp - 1) * func(b, k) / b;
      }
      n -= tmp10x * tmp;
      b--;
      tmp10x /= 10;
    }
  }
  std::cout << ans << endl;
  return 0;
}
