#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  vector<int> vp;
  map<int, int> mp;
  for (int i = 0; i < n; ++i) {
    int x;
    cin >> x;
    vp.push_back(x);
  }
  vector<int> vs;
  for (int i = 0; i < n; ++i) {
    int s;
    cin >> s;
    vs.push_back(s);
    mp[s] = max(vp[i], mp[s]);
  }
  int cnt = 0;
  for (int i = 0; i < k; ++i) {
    int s;
    cin >> s;
    if (mp[vs[s - 1]] == vp[s - 1])
      continue;
    else
      cnt++;
  }
  cout << cnt;
}
