func_code_string: #include <bits/stdc++.h>   using namespace std;   int n;   vector<pair<int, long long>> v[63];   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cin >> n;     long long sum = 0;     for (int i = 0; i < n; i++) {       int val;       long long mask;       cin >> val >> mask;       sum += val;       int j = 62;       while (!(mask & (1LL << j))) j--;       v[j].push_back(make_pair(val, mask));     }     if (sum > 0)       for (int j = 0; j < 63; j++)         for (auto& p : v[j]) p.first *= -1;     long long s = 0;     for (int j = 0; j < 63; j++) {       sum = 0;       for (auto& p : v[j]) {         p.second &= s;         int b = 0;         for (int k = 0; k < j; k++)           if (p.second & (1LL << k)) b++;         sum += (b % 2 ? -p.first : p.first);       }       if (sum < 0) s |= (1LL << j);     }     cout << s << endl;     return 0;   }   