#include<iostream>
#include<cstdio>
using namespace std;
typedef long long ll;
const int maxn=100010;
const int mod=998244353;
int B[maxn],C[maxn];
int main(){
    int t;
    cin>>t;
    while(t--){
        int n;
        cin>>n;
        for(int i=1;i<=n;i++){
            scanf("%d",&B[i]);
        }
        for(int i=1;i<=n;i++){
            scanf("%d",&C[i]);
        }
        ll ans=1,Min,Max;
        if(B[1]!=C[1]){
            cout<<0<<endl;
            continue;
        }else{
            Max=B[1];
            Min=C[1];
            for(int i=2;i<=n;i++){
                if(B[i]>Min||C[i]<Max||(B[i]<Min&&C[i]>Max)){
                    ans=0;break;
                }else{
                    if(B[i]==Min&&C[i]==Max){
                        ans=ans*(Max-Min+1-i+1)%mod;
                    }else{
                        Min=B[i];Max=C[i];
                    }
                }
            }
            cout<<ans<<endl;
        }
        
    }
    return 0;
}