#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;

#define getmid(l,r) ((l) + ((r) - (l)) / 2)
#define MEM(a,b) memset(a,b,sizeof(a))
#define MP(a,b) make_pair(a,b)
#define PB push_back
#define scan(x) scanf("%d",&x)

typedef long long ll;
typedef pair<ll,ll> pii;
const double eps = 1e-8;
const int INF = (1 << 30) - 1;
const ll mod = 998244353;
const int MAXN = 200010;

int T,n;
int B[MAXN],C[MAXN];

int main(){
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        for(int i = 1; i <= n; ++i) scanf("%d",&B[i]);
        for(int i = 1; i <= n; ++i) scanf("%d",&C[i]);
        if(n == 1){
            if(B[1] == C[1]) printf("1\n");
            else printf("0\n");
            continue;
        }
        bool f = true;
        for(int i = 2; i <= n; ++i){
            if(B[i] > B[i - 1]) f = false;
            if(C[i] < C[i - 1]) f = false;
            if(B[i] != B[i - 1] && C[i] != C[i - 1]) f = false;
            if(!f) break;
        }
        if(!f){
            printf("0\n");
            continue;
        }
        ll ans = 1;
        int L = B[1],R = B[1];
        for(int i = 2; i <= n; ++i){
            if(B[i] != B[i - 1]) continue;
            if(C[i] != C[i - 1]) continue;
            ans = ans * (C[i] - B[i] - i + 2) % mod;
        }
        printf("%I64d\n",ans);
    }
    return 0;
}