#include <bits/stdc++.h>
using namespace std;
const double pi = 3.141592653589793238;
const long long int inf = (long long int)10e16;
int main() {
  map<int, int> l;
  int n, m, k;
  cin >> n >> m >> k;
  int po[n + 1];
  for (int i = 1; i <= n; ++i) {
    cin >> po[i];
  }
  int s[n + 1];
  for (int i = 1; i <= n; ++i) {
    int x;
    cin >> x;
    s[i] = x;
    l[x] = max(l[x], po[i]);
  }
  int count = 0;
  for (int i = 0; i < k; ++i) {
    int x;
    cin >> x;
    if (po[x] == l[s[x]])
      l[s[x]] = 1e9;
    else
      count++;
  }
  cout << count << endl;
  ;
}
