c.cpp

#include <bits/stdc++.h>

#define ll long long
using namespace std;

const int MAXN = 1e5 + 10;
const int MOD = 1e9 + 7;

ll bin_power(ll x, ll y){
    if (y == 0)
        return 1;
    if (y & 1){
        return (bin_power(x, y - 1) * x) % MOD;
    }
    ll z = bin_power(x, y >> 1);
    return (z * z) % MOD;
}

ll calc(ll x){
    ll y = x;
    vector <int> vec;
    while(y){
        vec.push_back(y % 10);
        y /= 10;
    }
    reverse(vec.begin(), vec.end());
    vector <ll> ans(10, 0);

    int len = vec.size();
    int mx = 0;
    for (int i = 0; i < len; i++){
        for (int j = 0; j < vec[i]; j++){
            if (len - i - 1 == 0){
                (ans[max(j, mx)] += 1) %= MOD;
            }
            else{
                for (int k = 0; k <= 9; k++){
                     (ans[max(k, max(j, mx))] += (bin_power(k + 1, len - i - 1)
                                    - bin_power(k, len - i - 1) + MOD) % MOD) %= MOD;
                }
            }
        }
        mx = max(mx, vec[i]);
    }

    ans[mx]++;
    ll answer = 0;
    for (int i = 0; i <= 9; i++){
        (answer += (i * ans[i]) % MOD) %= MOD;
    }
    return answer;

}

int main(){

    ll l, r;
    cin >> l >> r;
    int sum = 0;
  /*  for (int k = 1; k <= 9; k++)
        sum += bin_power(k + 1, 3) - (bin_power(k, 3));
    cout << sum;*/
    //cout << calc(r) << ' ' <<  calc(l - 1) << endl;
    cout << (calc(r) - calc(l - 1) + MOD) % MOD;
}