#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=100005;
int n;
int l[N],r[N];
int lw[N],rw[N];
int ans,minl;
void w(int x){
	for(int i=30;i>=0;i--){
		if(pow(2,i)<=r[x]){
			rw[x]=i;break;
		}
	}
	for(int i=30;i>=0;i--){
		if(pow(2,i)<=l[x]){
			lw[x]=i;break;
		}
	}
}
void solve(){
	cin>>n;
	minl=1e10+10;
	for(int i=1;i<=n;i++){
		cin>>l[i]>>r[i];
		w(i);
	} 
	vector<int> nums;
	for(int i=1;i<=n;i++){
		minl=min(minl,r[i]);
		if(rw[i]==lw[i]) {
			nums.emplace_back(i);
		//	cout<<i<<endl;
		}
	}           
	int ans=minl;
	
	for(int i=0;i<nums.size();i++){
		cout<<nums.size()<<endl;
		int k=l[nums[i]]&ans,f=0;
		
		if(r[nums[i]]-pow(2,rw[nums[i]])>=ans&&l[nums[i]]-pow(2,rw[nums[i]])<=ans)continue;   
		
		for(int j=l[nums[i]]+1;j<=r[nums[i]];j++){
			k=max(ans&j,k);
			if(ans==ans&j){
				f=1;
				break;
			}
		}
		if(!f)ans=k;
	//	cout<<k<<"  ans: "<<ans<<endl;
	}               
	cout<<ans<<endl;             
	return;
}
signed main() {
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	//freopen("in.txt","r",stdin);
	//freopen("out.txt","w",stdout);
	int t=1;
	cin>>t;
	while(t--){
		solve();
	}
    return 0;
}