DigitDPTemplate

///http://www.spoj.com/problems/CPCRC1C/
#include<bits/stdc++.h>

using namespace std;

#define ll long long int
#define db(x) cout<<#x<<" -> "<<x<<endl

vector<int>digit;
const int mx = 83;
int sz = -1;
ll dp[10][2][2][83];

void init(ll n){
    digit.clear();
    while(n){
        digit.push_back(n%10);
        n/=10;
    }
    reverse(digit.begin(),digit.end());
    sz = digit.size();
    return ;
}

ll recur(int pos,bool small,bool start,int sum){
    if(pos==sz){
        return sum;
    }
    if(dp[pos][small][start][sum]!=-1){
        return dp[pos][small][start][sum];
    }
    int lim = (small)?9:digit[pos];
    ll ret = 0;
    if(! start){ ///
        for(int i=0; i<=lim; i++){
            ret+= recur(pos+1, small | i<digit[pos] , 0, sum+i);
        }
    }
    else{
        for(int i=1; i<=lim; i++){
            ret+= recur(pos+1, small | i<digit[pos], 0, sum+i);
        }
        ret+= recur(pos+1,1,1,0);
    }
    return dp[pos][small][start][sum]=ret;
}


ll fuck(ll n){
    if(n==0){
        return 0LL;
    }
    if(n<=9){
        ll temp = n*(n+1)/2;
        return temp;
    }
    init(n);
    memset(dp,-1,sizeof(dp));
    return recur(0,0,1,0);
}


int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    ll n,m;
    while(cin>>n>>m){
        if(n==-1 && m==-1){
            return 0;
        }
        ll f = fuck(n-1);
        ll s = fuck(m);
        ll samia = s-f;
        cout<<samia<<endl;
    }
    return 0;
}