#include <bits/stdc++.h>

using namespace std;

long long mod = 998244353;
vector <long long> fact;
vector <long long> tcaf;

const int MAXN = 1e6 + 1;

long long cnk(int n, int k) {
    return fact[n] * tcaf[k] % mod * tcaf[n - k] % mod;
}

long long ans(int l, int r, vector <int> &left, vector <int> &right, map <pair <int, int>, int> &mp) {
    if (l == r) {
        return 1;
    }
    auto it = mp.find({l, r});
    if (it == mp.end()) {
        return 0;
    }
    int m = it->second;

    long long ans1 = ans(l, m, left, right, mp);
    long long ans2 = ans(m + 1, r, left, right, mp);
    return ans1 * ans2 % mod * cnk(r - l - 1, m - l) % mod;
}

void solve() {
    int n;
    cin >> n;
    vector <int> left(n), right(n);
    for (auto &i: left) {
        scanf("%d", &i);
        --i;
    }
    for (auto &i: right) {
        scanf("%d", &i);
        --i;
    }
    map <pair <int, int>, int> mp;
    for (int i = 0; i < n; ++i) {
        mp[{left[i], right[i] + 1}] = i;
    }
    int a = ans(0, n, left, right, mp);
    printf("%d\n", a);
}

long long binpow(long long a, long long n) {
    if (n == 0) {
        return 1;
    }
    long long ans = binpow(a, n / 2);
    ans = ans * ans % mod;
    if (n % 2 == 1) {
        ans = ans * a % mod;
    }
    return ans;
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    fact.resize(MAXN);
    tcaf.resize(MAXN);
    fact[0] = 1;
    tcaf[0] = 1;
    for (int i = 1; i < MAXN; ++i) {
        fact[i] = fact[i - 1] * i % mod;
        tcaf[i] = binpow(fact[i], mod - 2);
    }

    int t;
    scanf("%d", &t);
    for (int i = 0; i < t; ++i) {
        solve();
    }
}