#include <bits/stdc++.h>
using namespace std;
int n, m, k;
const int maxm = 1e3 + 5;
int a[maxm], b[maxm];
priority_queue<int> q[maxm];
int main() {
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
  }
  for (int i = 1; i <= n; i++) {
    scanf("%d", &b[i]);
    q[b[i]].push(a[i]);
  }
  int num;
  int res = 0;
  while (k--) {
    scanf("%d", &num);
    if (a[num] < q[b[num]].top()) res++;
  }
  printf("%d\n", res);
  return 0;
}
