#include <bits/stdc++.h>
using namespace std;
void FastIO() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  cout.precision(15);
}
int main() {
  FastIO();
  int n, m, k, p, s, idx;
  cin >> n >> m >> k;
  vector<int> power;
  for (int i = 0; i < n; i++) {
    cin >> p;
    power.push_back(p);
  }
  vector<int> v(m + 1, INT_MIN), school;
  for (int i = 0; i < n; i++) {
    cin >> s;
    school.push_back(s);
    v[s] = ((v[s] < power[i]) ? power[i] : v[s]);
  }
  vector<int> vis(m + 1, 0);
  int cnt = 0;
  for (int i = 0; i < k; i++) {
    cin >> idx;
    if (power[idx - 1] == v[school[idx - 1]]) {
      if (vis[school[idx - 1]])
        cnt++;
      else
        vis[school[idx - 1]] = 1;
    } else
      cnt++;
  }
  cout << cnt << "\n";
  return 0;
}
