func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long mod = 998244353;   const long long INF = mod * mod;   const long double eps = 1e-8;   void solve() {     int n;     cin >> n;     vector<long long> val(n), mask(n);     long long sum = 0;     for (int i = 0; i < n; i++) {       cin >> val[i] >> mask[i];       sum += val[i];     }     if (sum < 0) {       for (int i = 0; i < n; i++) {         val[i] = -val[i];         sum = -sum;       }     }     long long ans = 0;     for (int i = 0; i < 62; i++) {       long long k = (long long)1 << i;       long long csum = 0;       for (int j = 0; j < n; j++) {         if (mask[j] < 2 * k && (mask[j] & k)) {           csum += val[j];         }       }       if (csum > 0) {         ans += k;         for (int j = 0; j < n; j++) {           if (mask[j] & k) {             val[j] = -val[j];           }         }       }     }     cout << ans << endl;   }   signed main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout << fixed << setprecision(10);     solve();     return 0;   }   