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

const int MaxN = 1e5, Pt = 998244353;
int T, n;
long long Min[MaxN + 5], Max[MaxN + 5];

int main()
{
    scanf("%d", &T);
    while(T--)
    {
        long long sum = 1;
        bool flag = 1;
        scanf("%d", &n);
        for(int i = 1; i <= n; i++) scanf("%I64d", &Min[i]);
        for(int i = 1; i <= n; i++) scanf("%I64d", &Max[i]);
        if(Min[1] != Max[1]) flag = 0;
        else
        {
            long long ans_Min = Min[1];
            long long ans_Max = Max[1];
            for(int i = 2; i <= n; i++)
            {
                if(Min[i] > Max[i]) {flag = 0; break;}
                if(Min[i] != ans_Min && Max[i] != ans_Max) {flag = 0; break;}
                if(Min[i] > ans_Min || Max[i] < ans_Max) {flag = 0; break;} 
                if(Min[i] == ans_Min && Max[i] == ans_Max)
                    sum = (sum * (ans_Max - ans_Min + 2 - i)) % Pt;
                if(Min[i] == ans_Min && Max[i] > ans_Max) ans_Max = Max[i];
                if(Min[i] < ans_Min && Max[i] == ans_Max) ans_Min = Min[i];
            }
        }
        if(flag == 0) printf("0\n");
        else printf("%I64d\n", sum);
    }
}