func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxN = 1000 + 5;   const int mod = 1000 * 1000 * 1000 + 7;   int a[65], b[65];   int main() {     ios_base::sync_with_stdio(false);     long long l, r;     cin >> l >> r;     for (int i = 0; l > 0; l /= 2, i++) a[i] = l % 2;     for (int i = 0; r > 0; r /= 2, i++) b[i] = r % 2;     int i;     for (i = 60; i >= 0 && a[i] == b[i]; i--)       ;     if (i == -1)       cout << 0 << endl;     else       cout << (1ll << (i + 1)) - 1 << endl;     return 0;   }   