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#include <bits/stdc++.h>

#define pb push_back

using namespace std;

typedef long long ll;
typedef vector<ll> vll;

const ll MOD = 1e9+7;

ll newton(ll a, ll b) {
    ll result = 1, j = 1;
    for (int i = 1; i <= a; ++i) {
        result *= i;
        if (j <= b && result % j == 0) {
            result /= j;
            j++;
        }
    }

    for (; j <= b; ++j)
        result /= j;

    for (int i = 1; i <= a-b; ++i)
        result /= i;

    return result % MOD;
}

ll si(ll a) {
    ll result = 1;
    for (int i = 1; i <= a; ++i) {
        result *= i;
    }

    return result;
}

ll solve()
{
    ll n, sum = 0, even = 0, odd = 0, ones = 0, zeros = 0, twos = 0;
    cin >> n;
    vll v(2*n);

    for (int i = 0; i < 2*n; ++i) {
        cin >> v[i];
        sum += v[i];
        if (i % 2 == 0) even += v[i];
        else odd += v[i];

        if (v[i] == 1) ones++;
        if (v[i] == 2) twos++;
        if (v[i] == 0) zeros++;
    }

    if (sum == 0 || sum == 4*n) {
        return newton(4*n - 2, 2*(n-1)) % MOD * ll(si(2*n)/pow(2, n)) % MOD * ll(si(2*n)/pow(2, n)) % MOD;
    }

    if (ones == 2*n) {
        return 2 * newton(4*n - 3, 2*(n-1)) % MOD * ll(si(2*n)/pow(2, n)) % MOD * ll(si(2*n)/pow(2, n)) % MOD;
    }

    if ((even == n && ones == n && odd == 0) || (even == 2*n && twos == n && odd == n && ones == n)) {
        return 4 * ll(si(2*n)/pow(2, n)) % MOD;
    }

    return 0;
}

int main()
{
    ios_base::sync_with_stdio(0);

    int t;
    cin >> t;

    while (t--) {
        cout << (solve() % MOD) << endl;
    }
}