#include <cstdio>
#include<bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 10;
int T, n;
int l[maxn], r[maxn], now[maxn];
int main ()
{
    cin>>T;
while (T--) {
ios::sync_with_stdio(false);
 cin.tie(0),cout.tie(0);

   cin>>n;
    for (int i = 1; i <= n; ++i)
       cin>>l[i]>>r[i], now[i] = 0;
    int ans = 0;
    for (int i = 31; i >= 0; --i) {
        bool flag = true;
        for (int j = 1; j <= n && flag; ++j) {
            int nl = now[j] | (1 << i), nr = now[j] | ((2 << i) - 1);
            if (nl > r[j] || nr < l[j])
            flag = false;
        }
        if (flag) {
            for (int j = 1; j <= n; ++j)
                now[j] |= 1 << i;
            ans |= 1 << i;
        }
                else {
            for (int j = 1; j <= n; ++j) {
                int nl = now[j] | (1 << i), nr = now[j] | ((2 << i) - 1);
//                if (nl <= r[j] && nr >= l[j] && nl - 1 <= l[j])
//                        now[j] |= 1 << i;
            }
        }

    }
   cout<<ans<<endl;
}

    return 0;
}