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

const int mx=100005;
long long b[mx],c[mx];


int main()
{
    int t;
    scanf("%d",&t);
    while (t--)
    {
        int n;
        scanf("%d",&n);
        for (int i=1;i<=n;i++) scanf("%I64d",&b[i]);
        for (int i=1;i<=n;i++) scanf("%I64d",&c[i]);
        if (b[1]!=c[1])
        {
            printf("0\n");
            continue;
        }
        long long ans=1;
        for (int i=2;i<=n;i++)
        {
            if (b[i]>b[i-1]||c[i]<c[i-1])
            {
                ans=0;
                break;
            }
            if ((b[i]<b[i-1]&&c[i]!=c[i-1])||(b[i]!=b[i-1]&&c[i]>c[i-1]))
            {
                ans=0;
                break;
            }
            if (c[i]-b[i]+1<i)
            {
                ans=0;
                break;
            }
            if (b[i]==b[i-1]&&c[i]==c[i-1])
            {
                ans=(ans*(c[i]-b[i]+2-i))%998244353;
            }
        }
        printf("%I64d\n",ans);
    }

}