#include<iostream>
#include<cstdio>
using namespace std;
int t,n;
const int N=3e5+10;
int a[N];
int f[N];
struct aa{
	int val,id;
	int zdz,cdz;
	int zdid,cdid;
};
void prt(aa x){
	cout<<x.id<<" "<<x.val<<" "<<x.zdid<<" "<<x.zdz<<" "<<x.cdid<<" "<<x.cdz<<endl;
}
aa dp[10];
int main(){
	cin>>t;
	while(t--){
		cin>>n;
		for(int i=1;i<=n;i++)scanf("%d",&a[i]);
		dp[1].val=a[1];
		dp[1].id=1;
		dp[0].val=1;
		dp[1].zdz=1;
		dp[1].zdid=a[1];
		
		for(int i=2;i<=n;i++){
		aa fn;
		fn.cdid=fn.cdz=fn.id=fn.val=fn.zdid=fn.zdz=0;
		fn.val=a[i];
		fn.id=i;
			for(int j=1;j<=dp[0].val;j++){
				if(dp[j].val==a[i])continue;
				if(dp[j].zdid==a[i]){
					if(!dp[j].cdz)continue;
					else {
						f[i]=max(f[i],dp[j].cdz+1);
						if(f[i]>fn.zdz){
							fn.zdz=f[i];
							fn.zdid=dp[j].val;
						}else{
							if(f[i]>fn.cdz){
								fn.cdz=f[i];
								fn.cdid=dp[j].val;
							}
						}
					}
				}else{
						f[i]=max(f[i],dp[j].zdz+1);
						if(f[i]>fn.zdz){
							fn.zdz=f[i];
							fn.zdid=dp[j].val;
						}else{
							if(f[i]>fn.cdz){
								fn.cdz=f[i];
								fn.cdid=dp[j].val;
							}
						}
					}
				}
				int flag=0,zxid=999999999,zxidd;
				for(int j=1;j<=dp[0].val;j++){
					if(dp[j].val==a[i])flag=j;
					if(dp[j].id<zxid){
						zxid=dp[j].id;
						zxidd=j;
					}
					//prt(dp[j]);
				}
			//	puts("");
				if(flag){
					dp[flag]=fn;
					continue;
				}
				if(dp[0].val<5){
					dp[0].val++;
					dp[dp[0].val]=fn;
				}
				else dp[zxidd]=fn;
			}
		int maxans=0;
		for(int i=1;i<=n;i++)maxans=max(maxans,f[i]);
		cout<<maxans<<endl;
		aa ff;
		ff.cdid=ff.cdz=ff.id=ff.val=ff.zdid=ff.zdz=0;
		for(int i=0;i<=5;i++)dp[i]=ff;
		for
		(int i=1;i<=n;i++)f[i]=0;
		
}
}