#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <map>
using namespace std;
//#pragma comment(linker, "/STACK:102400000000,102400000000")
#define FOR(i, n, m) for(int i = n; i <= m; i++)
#define REP(i, n, m) for(int i = n; i >= m; i--)
#define PB push_back
#define MP make_pair
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> PII;
const int INF = 1e9+7;
const int maxn = 100010;
const int mod = 998244353;


int b[maxn], c[maxn];

int main(){
        int t;
        cin >> t;
        while(t--){
            ll ans = 1;
            int n;
            cin >> n;
            FOR(i, 1, n) scanf("%d", &b[i]);
            FOR(i, 1, n) scanf("%d", &c[i]);
            int l = b[1], r = c[1];
            if(l != r) ans = 0;
            else{
                FOR(i, 2, n) {
                    if(ans == 0) break;
                    if(b[i] != l && c[i] != r) ans = 0;
                    else if(b[i] == l && c[i] == r){
                        if(i > r - l + 1) ans = 0;
                        else ans = ans * (r - l + 1 - i + 1) % mod; 
                        }
                    else if(b[i] == l && c[i] > r)  r = c[i];
                    else if(c[i] == r && b[i] < l) l = b[i];
                    else ans = 0;
                    }
                }
            cout << ans << endl;
            }
        return 0;
        }