/*
ID: 1292871202
LANG: C++
*/
#pragma comment(linker,"/STACK:102400000,102400000")
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <iomanip>
#include <cmath>
#include <algorithm>
#include <stack>
#include <queue>
#include <map>
#include <fstream>
#include <utility>

using namespace std;

typedef long long ll;

const int INF = 0x3f3f3f3f;
const int MAX = 0x7fffffff;
const ll LINF = 0x3f3f3f3f3f3f3f3fLL;
const ll LMAX = 0x7fffffffffffffffLL;
const double eps = 1e-9;
const double pi=acos(-1.0);

const int maxn = 100000+5;
const int maxm = 100000+5;
const int mod = 998244353;

#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1

int a[maxn];
int b[maxn];

int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    //cin.sync_with_stdio(false);
    //cout.sync_with_stdio(false);
    int t;
    cin>>t;
    while(t--)
    {
        int n;cin>>n;
        for(int i=1;i<=n;++i)
        {
            scanf("%d",&a[i]);
        }
        for(int i=1;i<=n;++i)
        {
            scanf("%d",&b[i]);
        }
        if(a[1]!=b[1])
        {
            printf("0\n");
            continue;
        }
        ll ans=1;
        int maxd=a[1],mind=a[1];
        for(int i=2;i<=n;++i)
        {
            if(a[i]>mind||b[i]<maxd)
            {
                ans=0;
                break;
            }
            if(a[i]!=mind&&b[i]!=maxd)
            {
                ans=0;
                break;
            }
            if(a[i]==mind&&b[i]==maxd)
                ans=ans*(maxd-mind+1-i+1)%mod;
            else
            {
                mind=a[i];
                maxd=b[i];
            }
        }
        printf("%I64d\n",ans);
    }
    return 0;
}