#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
const int N = 1e5 + 5;
#define int long long
typedef pair<int, int> PII;
#define MAX LONG_LONG_MAX
const int mod = 1e9 + 7;
PII ar[N];
void solve()
{
    int n;
    cin >> n;
    int maxs = 0x3f3f3f3f3f3f3f3f;
    for (int i = 1; i <= n;i ++)
    {
        int l, r;
        cin >> l >> r;
        maxs = min(maxs, r);
        ar[i] = {l, r};
    }

    int ans = maxs;
    for (int i = 1; i <= n;i ++)
    {
        if(ar[i].first <= maxs)
            continue;
        int l = ar[i].first, r = ar[i].second;

        int x = l;
        for (int i = 0; (1 << i) <= r; i ++)
        {
            if(x&(1<<i))
                continue;
            if(x+(1<<i) > r)
                break;
            x += (1 << i);
        }
        ans &= x;
    }
    cout << ans << endl;
}
signed main()
{
    int tcase;
    cin >> tcase;
    while (tcase--)
        solve();
    return 0;
}