#include<iostream>
#include<cstdio>
#include<cstring>
#define Maxn 100010
#define ll long long
using namespace std;

const int mod=998244353;
int mn[Maxn],mx[Maxn];
int b[Maxn],c[Maxn];
int main()
{
    int t,n;
    cin>>t;
    while(t--){
        cin>>n;
        for(int i=1;i<=n;i++) scanf("%d",b+i);
        for(int i=1;i<=n;i++) scanf("%d",c+i);
        if(b[1]!=c[1]){
            puts("0");
            continue;
        }
        mn[1]=mx[1]=b[1];
        ll ans=1;
        for(int i=2;i<=n;i++){
            //cout<<ans<<" "<<i<<endl;
            if(b[i]>mn[i-1]||c[i]<mx[i-1]){
                ans=0;
                break;
            }
            if(b[i]<mn[i-1]&&c[i]!=mx[i-1]||b[i]!=mn[i-1]&&c[i]>mx[i-1]){
                ans=0;
                break;
            }
            if(b[i]<mn[i-1]) mn[i]=b[i],mx[i]=mx[i-1];
            else if(c[i]>mx[i-1]) mx[i]=c[i],mn[i]=mn[i-1];
            else{
                if(mx[i-1]-mn[i-1]+1<i){
                    ans=0;
                    break;
                }
                ans=ans*(mx[i-1]-mn[i-1]+1-(i-1))%mod;
                mx[i]=mx[i-1],mn[i]=mn[i-1];
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}