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#include <bits/stdc++.h>
using namespace std;

#ifdef DEBUG
auto &operator<<(auto &o, pair<auto, auto> p) {
    return o << "(" << p.first << ", " << p.second <<")";
}
auto operator<<(auto &o, auto x)-> decltype(x.end(), o) {
    o << "{";int i = 0;
    for(auto e : x) o << ", "+!i++<<e;
    return o <<"}";
}
#define debug(x...) cerr << "["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(x)
#else
#define debug(...) {}
#endif

#define int long long
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define pb push_back
#define fi first
#define se second
typedef pair <int, int> pii;

int magic[6] = {0, 1, 540, 1701000, 19070251200, 562708626480000};
int magic2[6] = {0, 1, 360, 1020600, 10897286400, 312615903600000};

int mod = 1e9+7;

void test() {
    debug("TC______________________");
    int n; cin>>n;
    int cnt[3] = {0, 0, 0};
	
	vector <int> v(n*2);

    for (int i=0; i<2*n; ++i) {
      cin>>v[i];
	  cnt[v[i]]++;
    }

	if (cnt[0] == 2*n || cnt[2] == 2*n) {
		cout<<magic[n]%mod<<'\n';
		return ;
	}
	else if (cnt[1] == 2*n) {
		cout<<magic2[n]%mod<<'\n';
		return ;
	}
	else if (cnt[0] && cnt[2]) {
		cout<<0<<'\n';
		return ;
	}

	if (cnt[0] == 0) {
		vector <int> nowy(2*n);
		for (int i=0; i<2*n; ++i) {
			nowy[(i+1)%(2*n)] = 2 - v[i];
		}
		swap(v, nowy);
	}
	int blk = 0;
	for (int i=0; i<2*n; ++i) {
		if (v[i] == 0) {
			int j = i+1; 
			while (v[(j)%(2*n)] == 1) {
				j++;
			}
			if (j % 2 == 0) {
				cout<<0<<'\n';
				return ;
			}
			
			if ((i+1)%(2*n) != j) {
				blk++;
			}
		}
	}

	if (blk == 1) {
		cout<<magic[5]%mod<<'\n';
	}
	else {
		cout<<0<<'\n';
	}
}

signed main() {
  ios_base::sync_with_stdio(0); cin.tie(0);
  int t = 1; cin>>t;
  while (t--) {
    test();
  }
}