#include <bits/stdc++.h>
using namespace std;
const long long N = 200000;
long long p[N], s[N], r[N], maxi[N];
int main() {
  ios_base::sync_with_stdio(false);
  long long n, m, k, i, j, z, ans = 0;
  cin >> n >> m >> k;
  for (i = 0; i < n; i++) cin >> p[i];
  for (i = 0; i < n; i++) cin >> s[i];
  for (i = 0; i < k; i++) cin >> r[i];
  for (i = 0; i < n; i++) {
    z = s[i];
    if (p[i] > maxi[z]) maxi[z] = p[i];
  }
  for (i = 0; i < k; i++) {
    if (p[r[i] - 1] < maxi[s[r[i] - 1]]) ans++;
  }
  cout << ans << endl;
  return 0;
}
