#include <bits/stdc++.h>
#pragma GCC optimize("-O3")
using namespace std;
const long long N = 1e6 + 5;
void pairsort(long long a[], long long b[], long long n) {
  pair<long long, long long> pairt[n];
  for (long long i = 0; i < n; i++) {
    pairt[i].first = a[i];
    pairt[i].second = b[i];
  }
  sort(pairt, pairt + n);
  for (long long i = 0; i < n; i++) {
    a[i] = pairt[i].first;
    b[i] = pairt[i].second;
  }
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long isPrime(long long n) {
  if (n < 2) return 0;
  if (n < 4) return 1;
  if (n % 2 == 0 or n % 3 == 0) return 0;
  for (long long i = 5; i * i <= n; i += 6)
    if (n % i == 0 or n % (i + 2) == 0) return 0;
  return 1;
}
long long C(long long n, long long r) {
  if (r > n - r) r = n - r;
  long long ans = 1;
  for (long long i = 1; i <= r; i++) {
    ans *= n - r + i;
    ans /= i;
  }
  return ans;
}
long long mod = 998244353;
long long modexpo(long long x, long long p) {
  long long res = 1;
  x = x % mod;
  while (p) {
    if (p % 2) res = res * x;
    p >>= 1;
    x = x * x % mod;
    res %= mod;
  }
  return res;
}
long long t, n, k, a[N], b[N], ind[N], vis[N];
map<long long, long long> mp;
set<pair<long long, long long>> s1;
set<pair<long long, long long>, greater<pair<long long, long long>>> s2;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  cin >> t;
  while (t--) {
    cin >> n >> k, mp.clear(), s1.clear(), s2.clear();
    for (long long i = 1; i <= n; i++)
      cin >> a[i], ind[a[i]] = i, s1.insert({i, a[i]}), s2.insert({i, a[i]});
    for (long long i = 1; i <= k; i++) cin >> b[i], mp[b[i]]++;
    for (long long i = 1; i <= n; i++) vis[i] = mp[a[i]];
    long long ans = 1;
    for (long long i = 1; i <= k; i++) {
      long long options = 0;
      long long idx = ind[b[i]];
      auto it1 = s1.lower_bound({idx, n + 1});
      auto it2 = s2.lower_bound({idx, 0});
      bool flag1 = false;
      bool flag2 = false;
      if (it1 != s1.end()) {
        pair<long long, long long> p = *it1;
        options += (vis[p.first] == 0);
        flag1 |= (vis[p.first] == 0);
      }
      if (it2 != s2.end()) {
        pair<long long, long long> p = *it2;
        options += (vis[p.first] == 0);
        flag2 |= (vis[p.first] == 0);
      }
      vis[idx] = 0;
      ans *= options;
      ans %= mod;
      if (options == 2) {
        pair<long long, long long> p = *it1;
        s1.erase(p), s2.erase(p);
      }
      if (options == 1) {
        pair<long long, long long> p;
        if (flag1 == true)
          p = *it1;
        else
          p = *it2;
        s1.erase(p), s2.erase(p);
      }
    }
    cout << ans << "\n";
  }
  return 0;
}
