#include <bits/stdc++.h>
using namespace std;
using ll = long long;
map<int, int> mx;
void solve() {
  int n, m, k;
  cin >> n >> m >> k;
  vector<int> a(n), b(n);
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
  }
  for (int i = 0; i < n; ++i) {
    cin >> b[i];
  }
  for (int i = 0; i < n; ++i) {
    mx[b[i]] = max(mx[b[i]], a[i]);
  }
  int s = 0;
  for (int i = 0; i < k; ++i) {
    int t;
    cin >> t;
    int f = mx[b[t - 1]];
    int r = a[t - 1];
    if (f != r) {
      s++;
    }
  }
  cout << s;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  solve();
  return 0;
}
