#include <cstdio>
#include <cstring>
#include <algorithm>

const int Mod = 998244353;

int n, min[100005], max[100005];

namespace BIT {
    int c[100005];
    
#define lowbit(x) ((x) & -(x))
    
    void init(int lim) {
        for (int i = 1; i <= lim; ++i)
            c[i] = lowbit(i);
    }
    
    void modify(int pos, int val) {
        for (int i = pos; i <= n; i += lowbit(i))
            c[i] += val;
    }
    
    int query(int pos) {
        int ret = 0;
        for (int i = pos; i > 0; i -= lowbit(i))
            ret += c[i];
        return ret;
    }
}

int main() {
    int T; scanf("%d", &T);
    while (T--) {
        scanf("%d", &n);
        for (int i = 1; i <= n; ++i) scanf("%d", min + i);
        for (int i = 1; i <= n; ++i) scanf("%d", max + i);
        
        BIT::init(n);
        bool flag = max[1] == min[1];
        int ans = 1;
        for (int i = 1; i <= n; ++i) {
            if (max[i] < min[i] || (i != 1 && (max[i] < max[i - 1] || min[i] > min[i - 1] || (max[i] > max[i - 1] && min[i] < min[i - 1])))) {
                flag = 0; break;
            }
            if (max[i] > max[i - 1]) BIT::modify(max[i], -1);
            if (min[i] < min[i - 1]) BIT::modify(min[i], -1);
        }
        for (int i = 1; i <= n; ++i) if (max[i] == max[i - 1] && min[i] == min[i - 1]) {
            int tmp = BIT::query(max[i]) - BIT::query(min[i] - 1);
            if (tmp < 0) flag = 0;
            ans = 1ll * ans * tmp % Mod;
            BIT::modify(min[i], -1);
        }
        printf("%d\n", flag ? ans : 0);
    }
    return 0;
}