func_code_string: #include <bits/stdc++.h>   using namespace std;   int cnt, h;   bool f = true;   int main() {     long long s, x;     cin >> s >> x;     h = sizeof(long long) * 8 - __builtin_clzll(max(s, x)) - 1;     for (; h >= 0; h--) {       if (x & (1LL << h))         cnt++, s -= (1LL << h);       else if (s >= (1LL << h + 1))         s -= (1LL << h + 1), f = false;     }     if (s || (cnt < 2 && f))       cout << 0 << endl;     else       cout << (1LL << (cnt)) - f * 2 << endl;     return 0;   }   