#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int N=2e6+10;
const int M=0;
const int MOD=1e9+7;
const int MAXX=2147483647;
ll n,m;
int a[N];
int main()
{
    freopen("whz_number.in","r",stdin);
    freopen("whz_number.out","w",stdout);
    
    a[0]=1;
    for(int i=1;i<=N;i++){
        int t=i;
        while(t>0){
            if(t%10==0) a[i]++;
            t/=10;
        }
    }
    for(int i=1;i<=N;i++) a[i]+=a[i-1];
    while(scanf("%lld%lld",&n,&m)!=EOF){
        if(n>N) break;
        int ma=-999;
        for(int i=0;i<=n;i++)
        {
            int ans;
            if(i!=0) ans=a[n]-a[i-1];
            else ans=a[n];
            if(ans==m) ma=max(ma,i);
        }
        cout<<ma<<endl;
    }
    return 0;
}