#include <bits/stdc++.h>
using namespace std;
int in() {
  int ret;
  cin >> ret;
  return ret;
}
const int N = 1e6 + 10, INF = 1e9 + 7;
int n, k, m, p[N], second[N], c[N], ans;
bool vis[N];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m >> k;
  for (int i = 1; i <= n; i++) cin >> p[i];
  for (int i = 1; i <= n; i++) {
    cin >> second[i];
    c[second[i]] = max(c[second[i]], p[i]);
  }
  for (int i = 0; i < k; i++) {
    int x = in();
    if (p[x] == c[second[x]] && !vis[second[x]])
      vis[second[x]] = 1;
    else
      ans++;
  }
  cout << ans << '\n';
  return 0;
}
