#include<bits/stdc++.h>
using namespace std;
const int N = 1e5+5;
inline int read(){
	int s = 0;char ch = getchar();
	while(ch<'0'||ch>'9')ch = getchar();
	while(ch>='0'&&ch<='9'){s = (s<<1)+(s<<3)+ch-'0';ch = getchar();}
	return s;
}
int n,a[N],cnt[N],T,sum[N],r[N];
void clar(int* arr){
	for(int i = 1;i<=n;i++)arr[i] = 0;
}
void solve1(){
	int ans = 0,ansl,ansr;
	int nk[105],ct;
	for(int i = 1;i<=n;i++){
		clar(cnt);
		clar(sum);
		for(int j = i;j<=n;j++){
			sum[cnt[a[j]]]--;
			sum[++cnt[a[j]]]++;
			ct = 0;
			for(int k = 1;k<=n;k++){
				if(sum[k])nk[++ct] = k;
			}
			for(int k = 1;k<=ct;k++){
				if(ans<nk[k]){
					ans = nk[k];
					ansl = i,ansr = j;
				}
				for(int t = 1;t<k;t++){
					if((nk[k]|nk[t])>ans){
						ans = nk[k]|nk[t];
						ansl = i,ansr = j;
					}
				}
			}
		}
	}
//	cout << ans << '\n';
	clar(cnt);
	for(int i = ansl;i<=ansr;i++)cnt[a[i]]++;
	for(int i = 1;i<=n;i++){
		for(int j = 1;j<=n;j++){
			if((cnt[i]|cnt[j])==ans){
				cout << ans << '\n';
//				cout << ansl << ' ' << ansr << '\n'
//				<< i << ' ' << j << '\n';
				return;
			}
		}
	}
}
void solve2(){
	int mx1 = 0,mx2 = 0;
	clar(cnt);
	for(int i = 1;i<=n;i++){
		r[a[i]] = i;
		cnt[a[i]]++;
	}
	for(int i = 1;i<=n;i++){
		if(cnt[i]>=cnt[mx1]){
			mx2 = mx1;
			mx1 = i;
		}else if(cnt[i]>cnt[mx2])mx2 = i;
	}
	int c;
	if(!cnt[mx2]){
		cout << cnt[mx1] << '\n';
//		cout << 1 << ' ' << n << '\n';
//		cout << mx1 << ' ' << mx1 << '\n';
		return;
	}
	for(c = 1<<20;c;c>>=1){
		if((cnt[mx1]&c)&&(cnt[mx2]&c))break;
	}
	for(int i = n;i>=1;i--){
		if(!(cnt[mx1]&c)||!(cnt[mx2]&c)){
			cout << (cnt[mx1]|cnt[mx2]) << '\n';
//			cout << 1 << ' ' << i << '\n';
//			cout << mx1 << ' ' << mx2 << '\n';
			return; 
		}
		cnt[a[i]]--;
	}
	return;
}
int main(){
//	freopen("ttheal.in","r",stdin);
//	freopen("ttheal.out","w",stdout);
	T = read();
	while(T--){
		n = read();
		for(int i = 1;i<=n;i++)a[i] = read();
		if(n<=100)solve1();
		else solve2();
	}
	return 0;
}