#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, k, i, j, d, h = 0;
  cin >> n >> m >> k;
  vector<pair<int, int> > v;
  int a[n + 1], b[n + 1];
  for (i = 1; i <= n; i++) {
    cin >> a[i];
  }
  for (i = 1; i <= n; i++) {
    cin >> b[i];
  }
  for (i = 1; i <= n; i++) {
    v.push_back(make_pair(-a[i], b[i]));
  }
  sort(v.begin(), v.end());
  for (j = 1; j <= k; j++) {
    cin >> d;
    for (i = 0; i < n; i++) {
      if (v[i].second == b[d]) {
        if (-v[i].first > a[d]) {
          h++;
        }
        b[d] = 1000;
      }
    }
  }
  cout << h << endl;
  return 0;
}
