func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     long long l, r;     cin >> l >> r;     string s_l = to_string(l), s_r = to_string(r);     long long m = s_l.length(), n = s_r.length();     if (m == n) {       long long num = 4, mx = 9;       for (long long i = 1; i < n; i++) {         num = num * 10 + 9;         mx = mx * 10 + 9;       }       if (l > num + 1) {         cout << 1ll * l * (mx - l) << endl;       } else if (r < num) {         cout << 1ll * r * (mx - r) << endl;       } else {         cout << 1ll * num * (mx - num) << endl;       }     } else {       long long num = 4, mx = 9;       for (long long i = 1; i < n; i++) {         num = num * 10 + 9;         mx = mx * 10 + 9;       }       long long final = min(num, r);       cout << 1ll * final * (mx - final) << endl;     }     return 0;   }   