#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e5+10;
int cnt[N];
int l[N],r[N];
void slove()
{
	
	int ans;
	int minr = 1e9+1;
	int n;
	cin>>n;
	for(int i = 1 ; i <= n ; i++ )
	cnt[i] = 0;
	int flag ;
	for(int i = 1; i <= n ; i++ )
	{
		cin>>l[i]>>r[i];
		if(minr>r[i])
		{
			minr = r[i];
			flag = i;
		}
	}
	if(n==1)
	{
		cout<<r[1]<<endl;
		return ;
	}
	for(int i = 1; i <= n ; i++ )
	{
		if(i==flag) continue;
		while(r[i]>0)
		{
			cnt[i]++;
			r[i]/=2;
		}
	}
/*	for(int i = 1; i <= n ; i++ )
	{
		cout<<cnt[i]<<" ";
	}*/
	for(int i = 1 ; i <= n ; i++)
	{
		if(i==flag) continue;
		int y = cnt[i] - 1;
		int num = pow(2,y);
		ans = minr & ( num - 1 );
	}
	cout<<ans<<endl;
}
signed main()
{
	int tcase;
	cin>>tcase;
	while(tcase--)
	{
		slove();
	}
}
/*
1
3
0 8
2 6
3 9
4 0 4*/