#include<bits/stdc++.h>
using namespace std;
const int maxS = 1e4 + 10;
const int maxn = 100 + 10;
int cnt[maxS], ar[maxS], cnt_easy[maxS];
bitset<maxS> dp;

void print(){
    for (int i = 0; i < maxS; i++)
	cout << cnt[i] << ' ';
    cout << endl;
}

int solve(){
    memcpy(cnt_easy, cnt, sizeof cnt);
    //print();
    dp.reset();
    for (int i = 1; i < maxS/2; i++)
	if (cnt[i]){
	    int t = cnt[i]-1>>1;
	    cnt[i<<1]+=t;
	    cnt[i]&=1;
	    if (!cnt[i]) cnt[i]=2;
	}
    dp[0] = 1;
    for (int i = 1; i < maxS; i++)
	while (cnt[i]--)
	    dp |= dp<<i;
    memcpy(cnt, cnt_easy, sizeof cnt);

    return dp.count();
}

int32_t main(){
    int t;
    cin >> t;
    while (t--)
	{
	    int n, ans = 0;
	    cin >> n;
	    memset(cnt, 0, sizeof cnt);
	    for (int x, i = 0; i < n; i++)
		cin >> x, cnt[x]++;
	    for (int i = 1; i < maxS; i++)
		if (cnt[i])
		    for (int j = i + 1; j < maxS; j++)
			if(cnt[j]){
			    cnt[i]--;
			    cnt[j]--;
			    ans = max(ans, solve());
			    cnt[i]++;
			    cnt[j]++;
			}
	    for (int i = 0 ; i < maxS; i++)
		if (cnt[i] >= 2){
		    cnt[i] -= 2;
		    ans = max(ans, solve());
		    cnt[i] += 2;
		}
	    if(n==1)
		cout << "2\n";
	    else if(n==2)
		cout << "4\n";
	    else
		cout << (ans<<2) << '\n';
	}
}