func_code_string: #include <bits/stdc++.h>   using namespace std;   unsigned long long f(unsigned long long x, int b) {     for (int i = 0; i < 64; i++)       if (__builtin_popcountll(x) < b) x |= 1ULL << i;     return x;   }   unsigned long long brute(unsigned long long l, unsigned long long r) {     unsigned long long ret = l;     for (unsigned long long i = l; i <= r; i++)       if (__builtin_popcountll(i) > __builtin_popcountll(ret)) ret = i;     return ret;   }   int main() {     int T;     scanf( %d , &T);     unsigned long long a, b;     while (T--) {       scanf( %llu%llu , &a, &b);       unsigned long long ans = a;       for (int i = __builtin_popcountll(a) + 1; i < 64; i++) {         unsigned long long v = f(a, i);         if (v <= b) ans = v;       }       printf( %lld n , ans);     }     return 0;   }   