#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int p[1000], s[1000], maximum[1500];
int main() {
  int n, m, k, x;
  cin >> n >> m >> k;
  for (int i = 1; i <= n; i++) cin >> p[i];
  for (int i = 1; i <= n; i++) {
    cin >> s[i];
    x = maximum[s[i]];
    x = max(x, p[i]);
    maximum[s[i]] = x;
  }
  ll ans = 0;
  for (int i = 1; i <= k; i++) {
    cin >> x;
    if (maximum[s[x]] != p[x]) ans++;
  }
  cout << ans << endl;
}
