#ifdef __GNUC__
#pragma GCC optimize "-O3"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define unordered_map __fast_unordered_map
template<class Key, class Value, class Hash = std::hash<Key>>
using unordered_map = __gnu_pbds::gp_hash_table<Key, Value, Hash>;
#else
#include <iostream>
#include <fstream>
#include <vector>
#include <deque>
#include <set>
#include <map>
#include <unordered_map>
#include <list>
#include <array>
#include <cstdlib>
#include <stack>
#include <string>
#include <queue>
#include <chrono>
#include <functional>
#include <limits>
#include <cmath>
#include <algorithm>
#include <random>
#include <regex>
#include <tuple>
#include <numeric>
#include <cassert>
#include <utility>
#include <bitset>
#include <complex>
#include <iomanip>
#include <ostream>
#include <sstream>
#include <ctime>
unsigned int __builtin_popcount(unsigned int x)
{
	int ret = 0;
	while(x)
	{
		ret += x & 1;
		x >>= 1;
	}
	return ret;
}
unsigned long long __builtin_popcountll(unsigned long long x)
{
	int ret = 0;
	while(x)
	{
		ret += x & 1LL;
		x >>= 1LL;
	}
	return ret;
}
long long __gcd(long long a, long long b)
{
	assert(a >= 0);
	assert(b >= 0);
	if (b == 0) return a;
	long long ret = __gcd(b, a % b);
	assert(ret);
	return ret;
}
int __gcd(int a, int b)
{
	assert(a >= 0);
	assert(b >= 0);
	if (b == 0) return a;
	int ret = __gcd(b, a % b);
	assert(ret);
	return ret;
}
#endif
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const ll INFLL = 2 * (ll)1e18 + 100;
#define for0(i, n) for(int i = 0; i < static_cast<int>(n); ++i)
#define for1(i, n) for(int i = 1; i <= static_cast<int>(n); ++i)
#define pb push_back
#define mp make_pair
#define all(v) v.begin(), v.end()
#define V vector<int>
#define VP vector<pair<int, int> >
#define FASTIO ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define index INDEX
template<class T> ostream &operator<<(ostream& os, const vector<T>& v) {
	if (v.empty()) return os;
	for (std::size_t i = 0; i < v.size() - 1; ++i) os << v[i] << ' ';
	return os << v.back();
}
template<class T> ostream &operator<<(ostream& os, const deque<T>& v) {
	if (v.empty()) return os;
	for (std::size_t i = 0; i < v.size() - 1; ++i) os << v[i] << ' ';
	return os << v.back();
}
template<class T> ostream &operator<<(ostream& os, const set<T>& v) {
	if (v.empty()) return os;
	auto aux = v.end(); --aux;
	for(auto it = v.begin(); it != aux; ++it)
	{
		os << *it << ' ';
	}
	return os << *aux;
}
template<class T> ostream &operator<<(ostream& os, const multiset<T>& v) {
	if (v.empty()) return os;
	auto aux = v.end(); --aux;
	for(auto it = v.begin(); it != aux; ++it)
	{
		os << *it << ' ';
	}
	return os << *aux;
}
template<class L, class R> ostream &operator<<(ostream &os, const pair<L,R>& P) {
	return os << P.first << " " << P.second;
}
template<class TH> void _dbg(const char *sdbg, TH h){ cerr << sdbg << " = " << h << '\n'; }
template<class TH, class... TA> void _dbg(const char *sdbg, TH h, TA... a) {
  while(*sdbg!=',') cerr << *sdbg++;
  cerr<<" = "<< h << ','; _dbg(sdbg + 1, a...);
}
#ifndef ONLINE_JUDGE
#define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (__VA_ARGS__)
#define cerr if(0)cout
#endif
ll generate_random() {
	const ll MAX_RANDOM = (ll)1e12 + 1;
	mt19937_64 rng_obfuscated$19937(chrono::steady_clock::now().time_since_epoch().count());
	return uniform_int_distribution<unsigned long long>(1LL, MAX_RANDOM)(rng_obfuscated$19937);
}
#define int ll /// might modify this sometimes
#ifdef int 
const int INFINT = INFLL;
#else
const int INFINT = 2 * (int)1e9 + 100;
#endif
const double PI = atan(1) * 4;
const double EPS = 1e-6; const int SEED = (int)1e3 + 7;
const int MOD = (int)1e9 + 7;
const int NMAX = (int)1e6 + 5;


int32_t main() {
	FASTIO; /// disable for interactive
#ifndef ONLINE_JUDGE
	double START_PROGRAM = clock();
#endif

	freopen("perle.in", "r", stdin);
	freopen("perle.out", "w", stdout);

	int t;
	cin >> t;
	while (t--)
	{
		string s;
		int n;
		cin >> n;
		for1(i, n)
		{
			int aux;
			cin >> aux;
			s.push_back((char)(aux + '0'));
		}
		if (s.size() == 1)
		{
			cout << "1\n";
			continue;
		}

		if (s.size() == 3 && s[0] == '1' && s[1] == '2')
		{
			cout << "1\n"; 
			continue;
		}

		int have_b = 0, have_c = 0;
		if (s[0] == '2' || s[0] == '1') have_b = 1;
		else have_c = 1;

		for(int i = 0; i < s.size(); ++i)
		{
			if(s[i] == '1')
			{
				if(have_b)
				{
					have_b--;
					i++;
					i++;
					if(i >= s.size() || s[i] != '3')
					{
						cout << "0\n";
						goto skip;
					}
					i++;
				//	i++;
					if(i >= s.size())
					{
						cout << "0\n";
						goto skip;
					}
					have_c++;
				}
				else if(have_c)
				{
					have_c--;
					i++;
					if(i >= s.size() || s[i] != '2')
					{
						cout << "0\n";
						goto skip;
					}
					i++;
					if(i >= s.size())
					{
						cout << "0\n";
						goto skip;
					}
				}
				else
				{
					cout << "0\n";
					goto skip;
				}
			}
			else if(s[i] == '2')
			{
				if(have_b)
				{
					continue;
				}
				else if(have_c)
				{
					have_c--;
				}
				else
				{
					cout << "0\n";
					goto skip;
				}
			}
			else
			{
				if(have_b)
				{
					cout << "0\n";
					goto skip;
				}
				else if(have_c)
				{
					have_b++;
				}
				else
				{
					cout << "0\n";
					goto skip;
				}
			}
		}
		if (have_b || have_c) cout << "0\n"; else cout << "1\n";

	skip:;
	}










#ifndef ONLINE_JUDGE
	double END_PROGRAM = clock();
	double ELAPSED_TIME = (END_PROGRAM - START_PROGRAM) / CLOCKS_PER_SEC;
	cerr << "\n\nElapsed Time: " << ELAPSED_TIME * 1000 << "\n";
#endif
	return 0;
}