#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
int n, m, k, x;
vector<int> s, p, top;
void work() {
  for (int i = 0; i < n; ++i) {
    cin >> s[i];
    top[s[i]] = max(top[s[i]], p[i]);
  }
  int ans = 0;
  for (int i = 0; i < k; ++i) {
    cin >> x;
    x--;
    if (p[x] < top[s[x]]) ans++;
  }
  cout << ans << endl;
}
int main() {
  cin >> n >> m >> k;
  s.resize(n);
  p.resize(n);
  top.resize(m + 1);
  for (int i = 0; i < n; ++i) cin >> p[i];
  work();
  return 0;
}
