func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     long long n, i, j, k, x, MOD = 1000000007, ans, a1, a2, b1, b2, a, b;     string s1, s2;     cin >> n >> s1 >> s2;     vector<vector<long long>> dp(n + 1, vector<long long>(4, 0));     dp[0][0] = 1;     for (i = 0; i < n; i++) {       for (j = 0; j < 4; j++) {         if (s1[i] ==  ? )           a1 = 0, a2 = 9;         else           a1 = s1[i] -  0 , a2 = a1;         if (s2[i] ==  ? )           b1 = 0, b2 = 9;         else           b1 = s2[i] -  0 , b2 = b1;         for (a = a1; a <= a2; a++) {           for (b = b1; b <= b2; b++) {             x = j;             if (a < b)               x |= 1;             else if (a > b)               x |= 2;             dp[i + 1][x] = (dp[i + 1][x] + dp[i][j]) % MOD;           }         }       }     }     ans = dp[n][3];     cout << ans <<   n ;     return 0;   }   