#include <iostream>
#include<string>
#include<set>
#include<map>
#include<vector>
#define ll long long int
using namespace std;



ll pow(ll b, ll e){

    if(e==0)
        return 1;
    if(e==1)
        return b;

    ll x = pow(b, e >> 1);
    if(e%2==0)
        return (x*x);
    else
        return (((x*x))*b);

}
int main()
{
    long long int a, b;
    cin>>a>>b;
    long long int sol=0;
    if(a>9)
        sol=0;
    else{
        if(b<=10){
            sol=b-a;
            cout<<sol;
            return 0;
        }
        ll bb=10-a;
        ll v10=10;
        ll p10=1;
        while(v10<=b){
            sol+=pow(bb, p10);
            v10*=10;
            p10++;
        }

        vector<int> st;
        ll baux=b;
        while(baux>0){
            st.push_back(baux%10);
            baux/=10;
        }
        bool ok=true;
        for(int i=st.size()-1;ok&& i>=0; i--){
            if(st[i]<a){
                ok=false;
            }
            else{
                ll c=st[i]-a;
                sol+=(c* pow(bb, i));
            }

        }
    }
    cout<<sol;
    return 0;
}