#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  int n, m, k, ans = 0;
  cin >> n >> m >> k;
  vector<int> a(n + 1), b(n + 1), c(k + 1);
  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 <= k; i++) cin >> c[i];
  for (int i = 1; i <= k; i++) {
    int curp = a[c[i]], curid = b[c[i]];
    for (int j = 1; j <= n; j++) {
      if (b[j] == curid && curp < a[j]) {
        ans++;
        a[c[i]] = 0;
        b[c[i]] = 0;
        break;
      }
    }
  }
  cout << ans << endl;
  return 0;
}
