#include <bits/stdc++.h>
using namespace std;
double pi = 2 * acos(0.0);
int OO = 0x3f3f3f3f;
long long gcd(long long a, long long b) { return b == 0 ? a : gcd(b, a % b); }
long long lcm(long long a, long long b) { return a * (b / gcd(a, b)); }
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long n, m, k, x, cnt = 0;
  cin >> n >> m >> k;
  long long Power[n], school[n], Max[m + 5];
  memset(Max, 0, sizeof Max);
  for (int i = 0; i < n; i++) cin >> Power[i];
  for (int i = 0; i < n; i++) cin >> school[i];
  for (int i = 0; i < n; i++) Max[school[i]] = max(Power[i], Max[school[i]]);
  for (int i = 0; i < k; i++) {
    cin >> x;
    if (Power[x - 1] != Max[school[x - 1]]) ++cnt;
  }
  cout << cnt;
  return 0;
}
