func_code_string: #include <bits/stdc++.h>   using namespace std;   string s[105];   int n, m;   int main() {     long long l, r;     cin >> l >> r;     int digit1, digit2;     digit1 = digit2 = 0;     long long l1, r1;     l1 = l;     r1 = r;     while (l1 != 0) {       l1 /= 10;       digit1++;     }     while (r1 != 0) {       r1 /= 10;       digit2++;     }     int digit = max(digit1, digit2);     long long min_val = 1;     long long max_val = 9;     digit--;     while (digit != 0) {       min_val *= 10;       digit--;       max_val *= 10;       max_val += 9;     }     if ((max_val + 1) / 2 >= l && (max_val + 1) / 2 <= r) {       cout << (max_val - (max_val + 1) / 2) * (max_val + 1) / 2 << endl;     } else if (r < (max_val + 1) / 2) {       cout << (max_val - r) * r << endl;     } else {       if (l < min_val)         cout << max((max_val - l) * l,                     (max_val - (max_val + 1) / 2) * (max_val + 1) / 2)              << endl;       else         cout << (max_val - l) * l << endl;     }     return 0;   }   