/* ***********************************************
Author        :Stomach_ache
Created Time  :Sun 17 Jul 2016 06:14:59 PM CST
File Name     :B.cpp
************************************************ */

#include <functional>
#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <sstream>
#include <numeric>
#include <utility>
#include <cassert>
#include <iomanip>
#include <vector>
#include <bitset>
#include <cstdio>
#include <string>
#include <cmath>
#include <ctime>
#include <queue>
#include <deque>
#include <stack>
#include <list>
#include <set>
#include <map>
#if __cplusplus > 201103L
#include <initializer_list>
#include <unordered_set>
#include <unordered_map>
#endif

using namespace std;

#define oo 0x3F3F3F3F
#define PB push_back
#define SZ(x) (int)((x).size())
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, a, b) for (int _end_ = (b), i = (a); i <= _end_; ++i)
#define ROF(i, a, b) for (int _end_ = (b), i = (a); i >= _end_; --i)

typedef unsigned int uint;
typedef long long int64;
typedef unsigned long long uint64;
typedef long double real;


int64 fpm(int64 b, int64 e, int64 m) { int64 t = 1; for (; e; e >>= 1, b = b * b % m) e & 1 ? t = t * b % m : 0; return t; }
template<class T> inline bool chkmin(T &a, T b) {return a > b ? a = b, true : false;}
template<class T> inline bool chkmax(T &a, T b) {return a < b ? a = b, true : false;}
template<class T> inline T sqr(T x) {return x * x;}
template <typename T> T gcd(T x, T y) {for (T t; x; ) t = x, x = y % x, y = t; return y; }

int c[100010];
void add(int x, int v) {
    while (x <= 100000) {
        c[x] += v;
        x += x & -x;
    }
}

int sum(int x) {
    int ret = 0;
    while (x > 0) {
        ret += c[x];
        x -= x & -x;
    }
    return ret;
}

int B[100010], C[100010];

const int MOD = 998244353;

int main(void) {
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    int T;
    scanf("%d", &T);
    for (int t = 1; t <= T; ++ t) {
        int n;
        scanf("%d", &n);
        for (int i = 1; i <= n; ++ i) {
            scanf("%d", B + i);
        }
        for (int i = 1; i <= n; ++ i) {
            scanf("%d", C + i);
        }

        memset(c, 0, sizeof(c));
        for (int i = 1; i <= n; ++ i) {
            if (i == B[1]) continue;
            add(i, 1);
        }

        int lb = B[1], ub = C[1];
        bool flag = (lb == ub ? true : false);
        int64 ans = 1;
        set<int> s;
        for (int i = 1; i <= n; ++ i) if (i != B[1]) s.insert(i);
        for (int i = 2; i <= n && flag; ++ i) {
            if (B[i] > lb || C[i] < ub) {
                flag = false;
                break;
            }
            if (lb == B[i] && ub == C[i]) {
                ans = ans * (sum(ub) - sum(lb)) % MOD;
                int p = *s.upper_bound(lb);
                add(p, -1);
                s.erase(p);
            } else if (lb > B[i] && ub == C[i]) {
                add(B[i], -1);
                lb = B[i];
                s.erase(B[i]);
            } else if (lb == B[i] && ub < C[i]) {
                add(C[i], -1);
                ub = C[i];
                s.erase(C[i]);
            } else {
                flag = false;
                break;
            }
        }

        if (!flag) ans = 0;
        printf("%lld\n", ans);
    }

    return 0;
}