#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<vector>
#include<string>
#include<queue>
#include<map>
#include<string>
#include<set>
#include<stack>
using namespace std;
typedef unsigned long long ll;
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
const int maxn = 1e5+1000;
int n;
int sum[maxn];
int b[maxn], c[maxn], z;
const ll mod = 998244353;
int lowbit(int t)
{
    return t&(-t);
}
void update(int pos,int c)
{
    while(pos<=n){
        sum[pos] += c;
        pos += lowbit(pos);
    }
}
int getsum(int pos)
{
    int s = 0;
    while(pos>0){
        s += sum[pos];
        pos -= lowbit(pos);
    }
    return s;
}
/*
void push_down(int rt)
{
    sum[rt] = sum[rt<<1]+sum[rt<<1|1];
}
void build(int l,int r,int rt)
{
    if(l==r){
        scanf("%d",&b[z]);
        sum[rt]+=num[b[z]];
        z++;
        return ;
    }
    int m = (l+r)>>1;
    build(lson);
    build(rson);
    push_down(rt);
}
int getsum(int L,int R,int l,int r,int rt,int flag)
{
    if(L<=l&&R>=r){
        if(flag) {
            flag = 0;
            sum[rt] -= 1;
        }
        return sum[rt]+1;
    }
    int m = (l+r)>>1;
    int res = 0;
    if(L<=m){
        res += getsum(L,R,lson);
    }
    if(R>m) res += getsum(L,R,rson);
    push_down(rt);
    return res;
}
void update(int L,int R,int l,int r,int rt)
{

}*/
int main()
{
    int T;
    cin>>T;
    while(T--)
    {
        scanf("%d",&n);
        memset(sum, 0, sizeof sum);
        z = 0;
        for(int i = 0; i < n; i++){
            scanf("%d",&b[i]);
            update(i+1,1);
        }
       // build(1,n,1);
        for(int i = 0; i < n; i++) scanf("%d",&c[i]);

        if(b[0]!=c[0]){
            printf("0\n"); continue;
        }
        int mis, mas, flag;
        ll ans;
        mis = mas = b[0];
        int temp = getsum(b[0])-getsum(b[0]-1);
        ans = temp;
        update(b[0],-1);
      //  cout<<"temp = "<<temp<<endl;
      //  cout<<"b[0] = "<<b[0]<<endl;

        for(int i = 1; i < n; i++){
       //     cout<<"i = "<<i<<endl;
            if(b[i]>mis){
                ans = 0; break;
            }else
            {
                if(b[i]==mis){
                    flag = 0;
                }else
                {
                    flag = 1;
                    mis = b[i];
                 //   int cnt = getsum(b[i],b[i],1,n,1,1);
                    int cnt = getsum(b[i])-getsum(b[i]-1);
                    ans = ans*cnt%mod;
                    update(b[i],-1);
                    cnt -= 1;
                    if(cnt<0){
                        ans = 0; break;
                    }
                }
            }
            if(c[i]<mas){
                ans = 0; break;
            }else
            {
                if(c[i]==mas){

                }else
                {
                    if(flag==1){
                        ans = 0; break;
                    }else
                    {
                        flag = 1;
                        mas = c[i];
                     //   int cnt = getsum(c[i],c[i],1,n,1,1);
                        int cnt = getsum(c[i])-getsum(c[i]-1);
                        update(c[i],-1);
                        ans = ans*cnt%mod;
                        cnt--;
                        if(cnt<0){
                            ans = 0; break;
                        }
                    }
                }
            }
            //zai min he mas range to find nums and a value;
            if(flag==0){
               // int cnt = getsum(mis,mas,1,n,1);
                int cnt = getsum(mas)-getsum(mis-1);
                if(cnt<=0){
                    ans = 0; break;
                }else
                {
                    ans = ans*cnt%mod;
                    update(mas,-1);
                }
            }
        }
        printf("%I64u\n",ans);
    }
    return 0;
}