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

#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(v) v.begin(),v.end()
typedef unsigned long long ll;
template <class T> using V=vector<T>;
template <class T> using VV=V<V<T>>;

int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  
  ll n,k;
  cin>>n>>k;
  k--;
  V<ll> A;
  if(n==0){
    cout<<0<<endl;
    return 0;
  }
  
  while(n){
    A.push_back(n%10+1);
    n/=10;
  }
  int a=A.size();
  V<ll> B(a);
  rep(i,a) B[i]=A[i];
  for(int i=1;i<a;i++) B[i]*=B[i-1];
  V<ll> C(a);
  for(int i=a-1;i>0;i--){
    C[i]=k/B[i-1];
    k%=B[i-1];
  }
  C[0]=k;
  ll tmp=1;
  ll ans=0;
  rep(i,a){
    ans+=C[i]*tmp;
    tmp*=10;
  }
  cout<<ans<<endl;
 
  return 0;
}