#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n, m, k;
  cin >> n >> m >> k;
  vector<int> st[105];
  int arr[101], sch[101];
  for (int i = 1; i <= n; i++) cin >> arr[i];
  for (int i = 1; i <= n; i++) {
    cin >> sch[i];
    st[sch[i]].push_back(arr[i]);
  }
  vector<int> vp[101];
  for (int i = 0; i < k; i++) {
    int ck;
    cin >> ck;
    vp[sch[ck]].push_back(arr[ck]);
  }
  int ans = 0;
  for (int i = 1; i < 101; i++) {
    if (vp[i].size()) {
      sort(begin(vp[i]), end(vp[i]));
      ans += vp[i].size() - 1;
      sort(begin(st[i]), end(st[i]));
      if (st[i].back() > vp[i].back()) ans += 1;
    }
  }
  cout << ans << endl;
}
