#include <bits/stdc++.h>
using namespace std;
struct Man {
  Man() : power(0), school(0), is_chosen(false) {}
  int power;
  int school;
  bool is_chosen;
};
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  Man people[101];
  for (int i = 0; i < n; i++) cin >> people[i].power;
  for (int i = 0; i < n; i++) cin >> people[i].school;
  for (int i = 0; i < k; i++) {
    int chosen;
    cin >> chosen;
    people[chosen - 1].is_chosen = true;
  }
  sort(people, people + n,
       [](Man& lhs, Man& rhs) { return lhs.power > rhs.power; });
  bool school_used[101] = {};
  int ans = 0;
  for (int i = 0; i < n; i++) {
    if (people[i].is_chosen && school_used[people[i].school]) ans++;
    school_used[people[i].school] = true;
  }
  cout << ans;
}
