#include<iostream>
#include<cstdio>
#include<cmath>
#include<string>
#include<queue>
#include<algorithm>
#include<stack>
#include<cstring>
#include<vector>
#include<list>
#include<set>
#include<map>
using namespace std;
#define ll __int64
#define esp 0.00000000001
const int N=1e5+10,M=1e7+10,inf=1e9+10;
const ll mod=998244353;
int a[N];
int b[N];
int main()
{
    int x,y,z,i,t;
    int T;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d",&x);
        ll ans=1;
        int flag=1;
        for(i=0;i<x;i++)
        scanf("%d",&a[i]);
        for(i=0;i<x;i++)
        scanf("%d",&b[i]);
        if(a[0]!=b[0])
        ans=0;
        for(i=1;i<x;i++)
        {
            if(a[i]!=a[i-1]&&b[i]!=b[i-1])
            ans=0;
            else if(a[i]>a[i-1])
            ans=0;
            else if(b[i]<b[i-1])
            ans=0;
            else if(a[i]!=a[i-1]||b[i]!=b[i-1])
            flag++;
            else
            {
                ans*=(b[i]-flag-a[i]+1);
                flag++;
                ans%=mod;
            }
        }
        printf("%I64d\n",ans);
    }
    return 0;
}