#include<cstdio>
#include<iostream>
#include<algorithm>
#include<queue>
#include<vector>
#include<string.h>
#include<map>
#define eps 1e-9
#define INF 0x7FFFFFFF
#define pi acos(-1)
#define mod 998244353
#define LL long long
#define nn 100005

using namespace std;

LL b[nn],c[nn];

int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        LL n,i;
        scanf("%lld",&n);
        for(i=1;i<=n;i++)
            scanf("%lld",&b[i]);
        for(i=1;i<=n;i++)
            scanf("%lld",&c[i]);
        bool bre=0;
        for(i=1;i<=n;i++)
        {
            if(c[i]<b[i])
            {
                bre=1;
                break;
            }
        }
        for(i=2;i<=n;i++)
        {
            if(b[i]>b[i-1])
            {
                bre=1;
                break;
            }
        }
        for(i=2;i<=n;i++)
        {
            if(c[i]<c[i-1])
            {
                bre=1;
                break;
            }
        }
        for(i=2;i<=n;i++)
        {
            if(b[i]<b[i-1]&&c[i]>c[i-1])
            {
                bre=1;
                break;
            }
        }
        if(bre)
        {
            puts("0");
            continue;
        }
        LL ans=1;
        //memset(vis,0,sizeof(vis));
        LL use=1,high,low,sum;
        for(i=1;i<=n;i++)
        {
            if(i==1)
            {
                if(b[i]!=c[i])
                {
                    puts("0");
                    ans=-1;
                    break;
                }
                low=high=b[i];
                //vis[b[i]]=1;
            }
            else
            {
                LL a1,a2;
                if(b[i]<b[i-1])
                    a1=b[i];
                else
                    a1=0;
                if(c[i]>c[i-1])
                    a2=c[i];
                else
                    a2=0;
                if(a1)
                {
                    low=a1;
                    use++;
                }
                else if(a2)
                {
                    high=a2;
                    use++;
                }
                else
                {
                    ans=(ans*(high-low+1-use))%mod;
                    use++;
                }
            }
        }
        if(ans!=-1)
            printf("%lld\n",ans);
    }
    return 0;
}