//#include <bits\stdc++.h>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <cstdlib>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <ctime>
#include <cmath>
#include <algorithm>

#define sqr(x) (x)*(x)
#define lson (p<<1)
#define rson (lson | 1)
#define eps 1e-10
#define pii pair<int,int>
#define mk(x,y) make_pair(x,y)

using namespace std;
typedef long long llg;
const int N = 1e5+10;
const llg oo = 998244353LL;
int b[N],c[N];
int main()
{
    int n,cas;
    scanf("%d",&cas);
    while(cas--)
    {
        scanf("%d",&n);
        bool flag = 1;
        for(int i=0;i<n;i++)
        {
            scanf("%d",&b[i]);
        }
        for(int i=0;i<n;i++)
        {
            scanf("%d",&c[i]);
        }
        if(b[0] != c[0]) flag = 0;
        llg ans = 1;
        llg l = b[0],r = c[0],tmp;
        for(int i=1;i<n;i++)
        {
            if(!flag || ans < 0) break;
            if(b[i]>l) flag = 0;
            if(c[i]<r) flag = 0;
            if(b[i]!=l && c[i]!=r) flag = 0;
            l = b[i];
            r = c[i];
            if(b[i]!=b[i-1] || c[i] != c[i-1]) continue;
            tmp = i;
            ans = (ans * (r-l+1LL-tmp) ) % oo;
            //if(r-l+1-i<=0) flag = 0;
        }
        if(flag == 0 || ans < 0) ans = 0;
        cout<<ans<<endl;
    }
    return 0;
}