#include <bits/stdc++.h>
using namespace std;
long long a[105], b[105], mx[105];
int main() {
  long long n, m, k;
  cin >> n >> m >> k;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  for (int i = 1; i <= n; i++) {
    cin >> b[i];
  }
  for (int i = 1; i <= n; i++) {
    mx[b[i]] = max(mx[b[i]], a[i]);
  }
  long long c = 0;
  for (int i = 1; i <= k; i++) {
    long long x;
    cin >> x;
    if (mx[b[x]] == a[x]) c++;
  }
  cout << k - c;
}
