func_code_string: #include <bits/stdc++.h>   using namespace std;   long long gen(int order) {     long long sum = 0;     while (order != 0) {       sum = (sum * 10) + 9;       order--;     }     return sum;   }   int main() {     long long l, r;     cin >> l >> r;     long long p = l, k = r;     int order = 0, sorder = 0;     while (k != 0) {       k = k / 10;       order++;     }     while (p != 0) {       p = p / 10;       sorder++;     }     if (sorder == order) {       long long max = gen(order);       if ((max - 1) / 2 <= r && l <= (max - 1) / 2) {         long long ans = ((max + 1) / 2) * ((max - 1) / 2);         cout << ans;       } else {         long long max = gen(order);         if (r < (max - 1) / 2) {           long long ans = r * (max - r);           cout << ans;         } else {           long long ans = l * (max - l);           cout << ans;         }       }     } else {       long long max = gen(order);       long long smax = gen(order - 1);       if (r >= (max - 1) / 2) {         long long ans = ((max + 1) / 2) * ((max - 1) / 2);         cout << ans;       } else {         if (l <= (smax + 1) / 2) {           if ((smax + 1) * (smax - 1) / 4 > r * (max - r)) {             cout << (smax + 1) * (smax - 1) / 4;           } else {             cout << r * (max - r);           }         } else {           if (l * (smax - l) > r * (max - r)) {             cout << l * (smax - l);           } else {             cout << r * (max - r);           }         }       }     }   }   