func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long N = 2e5 + 5, inf = 1e18, mod = 1e9 + 7;   const double PI = 3.1415926536;   int days[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};   bool is_prime(long long n) {     for (long long i = 2; i * i <= n; ++i) {       if (n % i == 0) {         return false;       }     }     return true;   }   inline long long getPow(long long a, long long b) {     long long res = 1ll, tp = a;     while (b) {       if (b & 1ll) {         res *= tp;       }       tp *= tp;       b >>= 1ll;     }     return res;   }   long long vec_mult(const pair<long long, long long> &t1,                      const pair<long long, long long> &t2,                      const pair<long long, long long> &t3) {     const long long &x1 = t1.first, y1 = t1.second;     const long long &x2 = t2.first, y2 = t2.second;     const long long &x3 = t3.first, y3 = t3.second;     return ((x2 - x1) * (y3 - y1) - (y2 - y1) * (x3 - x1));   }   void ok() {     cout <<  YES  << endl;     exit(0);   }   void no() {     cout <<  NO  << endl;     exit(0);   }   inline long long nxt() {     long long x;     cin >> x;     return x;   }   long long otr(long long num) {     long long cur = 0;     long long ct = 1;     while (num) {       cur += ct * (9 - num % 10);       num /= 10;       ct *= 10;     }     return cur;   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0), cout.tie(0);     long long l = nxt(), r = nxt();     long long t = 1ll;     long long ans = -1;     while (t <= r) {       long long left = max(l, t);       long long right = min(r, 10ll * t - 1);       while (right - left > 2) {         long long len = (right - left + 1) / 3;         long long t1 = left + len;         long long t2 = right - len;         if (t1 * otr(t1) >= t2 * otr(t2)) {           right = t2;         } else {           left = t1;         }       }       while (left <= right) {         ans = max(ans, left * otr(left));         left++;       }       t *= 10ll;     }     cout << ans;     return 0;   }   