#include <bits/stdc++.h>
using namespace std;
long long n, m, k;
long long p[100], s[100];
vector<long long> c;
map<long long, long long> mp;
void solve() {
  cin >> n >> m >> k;
  for (long long i = 0; i < n; i++) cin >> p[i];
  for (long long i = 0; i < n; i++) cin >> s[i];
  for (long long i = 0; i < k; i++) {
    long long x;
    cin >> x;
    c.push_back(x - 1);
  }
  for (long long i = 0; i < n; i++) mp[s[i]] = max(mp[s[i]], p[i]);
  long long ans = 0;
  for (long long i = 0; i < k; i++) {
    if (mp[s[c[i]]] != p[c[i]]) ans++;
  }
  cout << ans << endl;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  solve();
  return 0;
}
