#include <cstdio>

#include <cmath>

#include <cstring>

#include <iostream>

#include <algorithm>

#include <queue>

#include <vector>

#include <map>



using namespace std;



typedef long long LL;


int T,n,a[100005],b[100005],f[100005];
bool flag;
LL ans,dq;
const LL mod=998244353;

int main()

{
    scanf("%d",&T);
    while (T--)
    {
        scanf("%d",&n);
        for (int i=1;i<=n;++i) scanf("%d",&a[i]);
        for (int i=1;i<=n;++i) scanf("%d",&b[i]);
        a[0]=b[0]=0;
        flag=true;
        for (int i=2;i<=n;++i) if (a[i]>a[i-1]) flag=false;
        for (int i=2;i<=n;++i) if (b[i]<b[i-1]) flag=false;
        if (!flag)
        {
            printf("0\n");
            continue;
        }
        for (int i=1;i<=n;++i)
        {
            if (a[i]!=a[i-1])
            {
                f[i]=a[i];
                if (b[i]!=b[i-1])
                {
                    if (a[i]!=b[i]) flag=false;
                    if (!flag) break;
                }
            }
            else
            if (b[i]!=b[i-1])
            {
                f[i]=b[i];
            }
            else
            {
                f[i]=0;
            }
        }
        if (!flag)
        {
            printf("0\n");
            continue;
        }
        dq=0;
        ans=1;
        for (int i=1;i<=n;++i)
        {
            if (f[i]==0)
            {
                ans=ans*dq%mod;
                dq--;
            }
            else
            {
                if (i==1) continue;
                if (a[i]!=a[i-1]) dq+=a[i-1]-a[i]-1;
                if (b[i]!=b[i-1]) dq+=b[i]-b[i-1]-1;
            }
        } 
        printf("%I64d\n",ans);
    }

    return 0;

}