#include <cstdio>
#include <iostream>
using namespace std;
const int maxn=100005;
typedef long long ll;
const ll mod=998244353;
int T, n, B[maxn], C[maxn];
ll res;
int main()
{
    //freopen("in.txt", "r", stdin);
    scanf("%d", &T);
    while (T--) {
        res=1;
        scanf("%d", &n);
        for (int i=0; i<n; i++)
            scanf("%d", &B[i]);
        for (int i=0; i<n; i++)
            scanf("%d", &C[i]);
        bool flag=false;
        if (C[0]!=B[0]) {
            puts("0");
            continue;
        }
        for (int i=1; i<n; i++)
            if (B[i]>B[i-1]||C[i]<C[i-1]) {
                puts("0");
                flag=true;
                break;
            }
        if (flag)
            continue;
        for (int i=1; i<n; i++) {
            if (C[i]!=C[i-1]&&B[i]!=B[i-1]) {
                puts("0");
                flag=true;
                break;
            } else if (C[i]==C[i-1]&&B[i]==B[i-1])
                res=(res*(ll)(C[i]-B[i]-i+1))%mod;
        }
        if (flag)
            continue;
        cout<<res<<endl;
    }
    return 0;
}