#include <algorithm>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <vector>
using namespace std;

typedef long long ll;

const int N = 1e5 + 5;
const ll mod = 998244353;

int n;
int a[N], b[N];
int flag;
ll mul, ans;

void solve() {
    cin >> n;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    for (int i = 1; i <= n; i++)
        cin >> b[i];

    flag = 0;
    for (int i = n; i >= 1; i--) {
        if (flag)
            a[i] = 4 - a[i];
        if (a[i] == 2)
            flag ^= 1;
    }
    flag = 0;
    for (int i = n; i >= 1; i--) {
        if (flag)
            b[i] = 4 - b[i];
        if (b[i] == 2)
            flag ^= 1;
    }

    mul = 1, ans = 0;
    flag = 0;
    for (int i = n; i >= 1; i--) {
        if (a[i] > b[i]) {
            flag = 1;
            break;
        } else {
            flag = -1;
            break;
        }
    }
    for (int i = 1; i <= n; i++) {
        ll res = (a[i] - b[i]) * flag + mod;
        ans = (ans + res * mul % mod) % mod;
        mul = mul * 3ll % mod;
    }
    cout << ans << "\n";
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int T = 1;
    cin >> T;
    while (T--) {
        solve();
    }
    return 0;
}

/*

4
1
1
3
2
3 3
2 1
3
3 2 1
1 2 3
4
2 1 3 2
2 1 3 2

*/