#include<stdio.h>
#include<string.h>
#include<iostream>
#include<algorithm>
#include<ctype.h>
#define M 100005
#define Mod 998244353
int B[M],C[M],T,n;
int main(){
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        for(int i=1;i<=n;++i)scanf("%d",&B[i]);
        for(int i=1;i<=n;++i)scanf("%d",&C[i]);
        int ans=1,tmp=0,mx=C[1],mi=B[1];
        if(B[1]!=C[1])ans=0;
        for(int i=2;i<=n;++i){
            if(C[i]<B[i])ans=0;
            else if(C[i]<mx||B[i]>mi)ans=0;
            else if(C[i]!=mx&&B[i]!=mi)ans=0;
            else if(C[i]>mx&&B[i]==mi){tmp+=C[i]-mx-1;tmp%=Mod;mx=C[i];}
            else if(B[i]<mi&&C[i]==mx){tmp+=mi-B[i]-1;tmp%=Mod;mi=B[i];}
            else if(C[i]==mx&&B[i]==mi){
                ans=1ll*ans*tmp%Mod;
                tmp--;
                if(tmp<0)ans=0;
            }
        }
        printf("%d\n",ans);
    }
    return 0;
}