#include <iostream>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;

typedef long long LL;
const int MAXN = 1e5 + 10;
const LL MOD = 998244353;
int a[MAXN], b[MAXN];

int main() {
    //freopen("in.txt", "r", stdin);
    int T;
    scanf("%d", &T);
    while (T--) {
        int n;
        scanf("%d", &n);
        for (int i = 1; i <= n; ++i)
            scanf("%d", &a[i]);
        for (int i = 1; i <= n; ++i)
            scanf("%d", &b[i]);
        if (a[n] != 1 || b[n] != n || a[1] != b[1]) {
            puts("0");
            continue;
        }
        LL ans = 1;
        bool flag = true;
        for (int i = 2; i <= n && ans; ++i) {
            if (a[i] > a[i - 1] || b[i] < b[i - 1]) flag = false;
            if (a[i - 1] - a[i] != 0 && b[i] - b[i - 1] != 0) flag = false;
            if (a[i] > b[i])    flag = false;
            if (!flag) break;
            if (a[i] == a[i - 1] && b[i] == b[i - 1])
                ans = (ans * (b[i] - a[i] - i + 2)) % MOD;
        }
        if (!flag) {
            puts("0");
            continue;
        }
        printf("%I64d\n", ans);
    }
    return 0;
}
/*
7
7
4 1 1 1 1 1 1
4 4 7 7 7 7 7
*/