#include <iostream>
#include <algorithm>
using namespace std;

using ull=unsigned long long;

ull count(ull x){
    if (x==0) return 1;
    ull res=1;
    ull b=1;
    while (b<=x){
        ull p=x/(b*10);
        ull d=(x/b)%10;
        ull s=x%b;
        if (d == 0){
            res+=(p>0?(p-1)*b+s+1:0);
        } else {
            res+=p*b;
        }
        b*=10;
    }
    return res;
}

ull n,k;
ull tz,tg;

int main(){
//	freopen("in.in","r",stdin);
//	freopen("out.out","w",stdout);
	freopen("whz_number.in","r",stdin);
	freopen("whz_number.out","w",stdout);
    while (cin>>n>>k){
        tz=count(n);
        if (k == tz){
            cout<<0<<endl;
            continue;
        }
        tg=tz-k;
        ull left=0,right=n,ans=0;
        bool found=0;
        while (left<=right){
            ull mid=left+(right-left)/2;
            ull cnt=count(mid);
            if (cnt==tg){
                ans=mid;
                found=1;
                left=mid+1;
            }else if (cnt<tg){
                left=mid+1;
            }else{
                right=mid-1;
            }
        }
        if (found){
            cout<<ans+1<<endl;
        } else {
            cout<<0<<endl;
        }
    }
    return 0;
}