#include <bits/stdc++.h>

#define fs first
#define sc second
#define pb push_back
#define int long long

using namespace std;

int cnt[30];
signed main() {
    int q;
    cin >> q;
    int n = 0;
    for (int i = 0; i < q; i++) {
        int x, y;
        cin >> x >> y;
        for (int j = 0; j < 30; j++) {
            if (x & (1 << j))
                cnt[j] += y;
        }
        n += y;
    }
    int ans = 0;
    for (int i = 0; i < 30; i++) {
        if (n - cnt[i] < cnt[i]) {
            ans += (1 << i);
        }
    }
    cout << ans;
}