#include<map>
#include<set>
#include<queue>
#include<math.h>
#include<vector>
#include<string>
#include<stdio.h>
#include<string.h>
#include<iostream>
#include<algorithm>
#define N 100005
#define P 998244353
typedef long long ll;
typedef unsigned long long ull;
const int INF=1<<30;
const ll inf=1LL<<60;
using namespace std;
void Rd(int &res){
    char c;res=0;
    while(c=getchar(),c<48);
    do res=res*10+(c&15);
    while(c=getchar(),c>47);
}
void print(int k){
    if(!k)return;
    print(k/10);
    putchar(k%10^48);
}
void sc(int k){
    if(!k)putchar('0');
    else print(k);
    putchar('\n');
}
int T,n,b[N],c[N];
int f[N];
void solve(){
    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]);
    for(int i=2;i<=n;i++){
        if(b[i]>b[i-1]||c[i]<c[i-1]){
            printf("0\n");
            return;
        }
    }
    if(b[1]!=c[1]){
        printf("0\n");
        return;
    }
    int ans=1,cnt=0;
    for(int i=2;i<=n;i++){
        if(b[i]<b[i-1]&&c[i]>c[i-1]){
            printf("0\n");
            return;
        }else if(b[i]<b[i-1]){
            cnt+=b[i-1]-b[i]-1;
        }else if(c[i]>c[i-1]){
            cnt+=c[i]-c[i-1]-1;
        }else{
            ans=1LL*ans*cnt%P;
            cnt--;
        }
    }
    cout<<ans<<endl;
    
}
int main(){
    scanf("%d",&T);
    for(;T--;){
        solve();
    }
    return 0;
}