#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  int p[n];
  int s[n];
  for (int i = 0; i < n; ++i) {
    cin >> p[i];
  }
  for (int i = 0; i < n; ++i) {
    cin >> s[i];
  }
  unordered_map<int, set<int> > mem;
  for (int i = 0; i < n; ++i) {
    mem[s[i]].insert(p[i]);
  };
  int r = 0;
  int k_i;
  for (int i = 0; i < k; ++i) {
    cin >> k_i;
    if (*(mem[s[k_i - 1]].rbegin()) != p[k_i - 1]) r++;
  }
  cout << r << "\n";
  return 0;
}
