#include<iostream>
#include<vector>
#include<algorithm>
#include<cstring>
#define int ll
#define lc (rt<<1)
#define rc (rt<<1|1)
#define mid (l+r>>1)
#define rg register
#define pb push_back
#define ppb pop_back
#define mkp make_pair
#define prq_mn(x) priority_queue<x, vector<x>, greater<x> >
#define prq_mx(x) priority_queue<x, vector<x>, less<x> >
#define Clear(x) memset(x, -INF, n*sizeof(int))
#define fi first
#define se second
#define DEBUG printf("Debug on line %d\n", __LINE__)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
const int N = 2e5 + 5;
const int INF = 0x3f3f3f3f;

template <typename T> bool updmax(T& a, T b) {return a<b ? a=b, 1 : 0;}
template <typename T> bool updmin(T& a, T b) {return a>b ? a=b, 1 : 0;}

inline int read(){
	int n=0, f=1; char ch = getchar();
	for(; !isdigit(ch); ch=getchar()) if(ch == '-') f=-1;
	for(; isdigit(ch); ch=getchar()) n=n*10+ch-'0';
	return n*f;
}

int T;
int n, m;
int a[N];
vector<int> vec; 
int mx[2][N], mxk[2][N], smx[2][N], smxk[2][N];

void upd1(int x, int y, int val, int k){
//	printf("upd1(%d, %d, %d, %d, %d)\n", x, y, val, k);
	if(val > mx[x][y]){
		smx[x][y] = mx[x][y];
		smxk[x][y] = mxk[x][y];
		mx[x][y] = val;
		mxk[x][y] = k;
	} else if(k != mxk[x][y] && val > smx[x][y]){
		smx[x][y] = val;
		smxk[x][y] = k;
	}
}

void upd(int x1, int y1, int x2, int y2, int val, int ii){
//	printf("upd(%d, %d, %d, %d, %d, %d)\n", x1, y1, x2, y2, val, ii);
	if(!val || mxk[x2][y2] != a[ii]) upd1(x1, y1, mx[x2][y2]+val, val ? y2 : mxk[x2][y2]);
	if(!val || smxk[x2][y2] != a[ii]) upd1(x1, y1, smx[x2][y2]+val, val ? y2 : smxk[x2][y2]);
}

signed main(){
	T = read();
	while(T--){
		vec.clear();
		
		n = read();
		for(int i=1; i<=n; i++){
			a[i] = read();
			vec.pb(a[i]);
		}
		
		sort(vec.begin(), vec.end());
		vec.erase(unique(vec.begin(), vec.end()), vec.end());
		m = vec.size();
		for(int i=1; i<=n; i++){
			a[i] = lower_bound(vec.begin(), vec.end(), a[i]) - vec.begin() + 1;
//			printf("a[%d] = %d\n", i, a[i]);
		}
		
		
		Clear(mx[0]); Clear(mxk[0]); Clear(smx[0]); Clear(smxk[0]);
		Clear(mx[1]); Clear(mxk[1]); Clear(smx[1]); Clear(smxk[1]);
		mx[0][0] = 0;
		mxk[0][0] = 0;
		for(int ii=1; ii<=n; ii++){
			int i=ii&1, lst = (ii-1)&1;
			for(int j=0; j<=m; j++){
//				f[i][j][k] = max(f[i][j][k], f[lst][j][k]);
//				if(a[ii]!=j && a[ii]!=k) f[i][a[ii]][j] = max(f[i][a[ii]][j], f[lst][j][k] + 1);
				upd(i, j, lst, j, 0, -1);
				if(a[ii]!=j) upd(i, a[ii], lst, j, 1, ii);
			}
			
			Clear(mx[lst]); Clear(mxk[lst]); Clear(smx[lst]); Clear(smxk[lst]);
//			for(int j=0; j<=m; j++){
//				printf("mx[%d][%d] = %d\n", ii, j, mx[i][j]);
//				printf("mxk[%d][%d] = %d\n", ii, j, mxk[i][j]);
//				printf("smx[%d][%d] = %d\n", ii, j, smx[i][j]);
//				printf("smxk[%d][%d] = %d\n\n", ii, j, smxk[i][j]);
//			}
		}
		
		int ans = -INF;
		for(int j=0; j<=m; j++){
			ans = max(ans, mx[n&1][j]);
		}
		printf("%lld\n", ans);
	}
}

/*
1
10
2 1 2 2 1 2 1 2 3 2 
*/