#include <bits/stdc++.h>
using namespace std;

#define SZ(a) (int)a.size()
#define ALL(a) a.begin(), a.end()
#define FOR(i, a, b) for (int i = (a); i<(b); ++i)
#define RFOR(i, b, a) for (int i = (b)-1; i>=(a); --i)
#define MP make_pair
#define PB push_back
#define F first
#define S second
#define FILL(a, b) memset(a, b, sizeof(a))

typedef long long LL;
typedef pair<int, int> PII;
typedef vector<int> VI;

const int MAX = 1 << 17;

int n;
int l[MAX], r[MAX];

bool ok(int x) {
	FOR(i, 0, n) {
		if (l[i] == r[i]) {
			if ((r[i] & x) != x) {
				return false;
			}
		}
		int j = 32 - __builtin_clz(l[i] ^ r[i]);
		int m = (1 << j) - 1;
		if (((l[i] & x) >> j) != (x >> j)) {
			return false;
		}
		if (((x >> (j - 1)) & 1) == 1 && (x & m) > (r[i] & m)) {
			return false;
		}
	}
	return true;
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int t;
	cin >> t;
	while (t--) {
		cin >> n;
		FOR(i, 0, n) {
			cin >> l[i] >> r[i];
		}
		int x = 0;
		RFOR(bit, 30, 0) {
			if (ok(x | (1 << bit))) {
				x |= 1 << bit;
			}
		}
		cout << x << "\n";
	}
	return 0;
}