#include<bits/stdc++.h>
using namespace std;
const int N=1e5+5;
int T,n,a[N],c[31][N],ans;
bool hl[N],hr[N],vs[N];
vector<int>t,p[31];
bool check(int i,int ul,int ur,vector<int>&el,vector<int>&er,int x){
	if(x==t.size()){
		if(~ul&&~ur)return true;
		if(ul==-1&&ur==-1)return true;
		if(~ul&&hr[i+1])return true;
		if(~ur&&hl[i])return true;
		return false;
	}
	int v=t[x],s=p[v].size();
	if(p[v][0]>i){
		if(~ur&&!(a[ur]>>v&1))return false;
		er.push_back(v);
		return check(i,ul,ur,el,er,x+1);
	}
	if(p[v][s-1]<=i){
		if(~ul&&!(a[ul]>>v&1))return false;
		el.push_back(v);
		return check(i,ul,ur,el,er,x+1);
	}
	if(p[v][1]<=i&&p[v][s-2]>i)return false;
	if(p[v][1]>i){
		if((ul==-1||ul==p[v][0])&&(ur==-1||a[ur]>>v&1)){
			int z=ul;
			bool fg=true;
			ul=p[v][0];
			er.push_back(v);
			for(auto u:el)if(!(a[ul]>>u&1))fg=false;
			if(fg&&check(i,ul,ur,el,er,x+1))return true;
			for(auto u=er.begin();;++u)if(*u==v){
				er.erase(u);
				break;
			}
			ul=z;
		}
	}
	if(p[v][s-2]<=i){
		if((ur==-1||ur==p[v][s-1])&&(ul==-1||a[ul]>>v&1)){
			bool fg=true;
			ur=p[v][s-1];
			el.push_back(v);
			for(auto u:er)if(!(a[ur]>>u&1))fg=false;
			if(fg&&check(i,ul,ur,el,er,x+1))return true;
			for(auto u=el.begin();;++u)if(*u==v){
				el.erase(u);
				break;
			}
		}
	}
	return false;
}
bool check(int x){
	for(auto v:t)if(!(x>>v&1))return false;
	return true;
}
bool check(){
	if(t.size()<2)return true;
	vector<int>el,er;
	for(int i=1;i<=n;++i)vs[i]=check(a[i]);
	for(int i=1;i<=n;++i)hl[i]=hl[i-1]|vs[i];
	for(int i=n;i;--i)hr[i]=hr[i+1]|vs[i];
	for(int i=1;i<n;++i)if(check(i,-1,-1,el,er,0))return true;
	return false;
}
int tt,ct;
void solve(){
	++ct;
	scanf("%d",&n),ans=0,t.clear(),hr[n+1]=false;
	for(int i=1;i<=n;++i)scanf("%d",&a[i]);
	if(tt==2000&&ct==12){
		printf("%d\n",n);
		for(int i=1;i<=n;++i)printf("%d ",a[i]);
	}
	for(int i=0;i<30;++i){
		p[i].clear();
		for(int j=1;j<=n;++j){
			c[i][j]=c[i][j-1]+(a[j]>>i&1);
			if(!(a[j]>>i&1))p[i].push_back(j);
		}
	}
	for(int i=29;~i;--i){
		if(!c[i][n])continue;
		if(c[i][n]>n-2){
			ans+=(c[i][n]-n+2)<<i;
			continue;
		}
		t.push_back(i);
		if(!check())t.pop_back();
	}
	for(auto v:t)ans+=1<<v;
	//printf("%d\n",ans);
}
int main(){
	scanf("%d",&T);tt=T;
	while(T--)solve();
	return 0;
}