#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  int *mas = new int[n];
  for (int i = 0; i < n; i++) cin >> mas[i];
  int *sch = new int[n];
  for (int i = 0; i < n; i++) cin >> sch[i];
  int *mS = new int[m];
  for (int i = 0; i < m; i++) mS[i] = 0;
  for (int i = 0; i < n; i++) {
    if (mS[sch[i] - 1] <= mas[i]) mS[sch[i] - 1] = mas[i];
  }
  int ans = 0;
  for (int i = 0; i < k; i++) {
    int ins;
    cin >> ins;
    if (mS[sch[ins - 1] - 1] > mas[ins - 1]) ans++;
  }
  cout << ans;
}
