/* -*- coding: utf-8 -*-
 *
 * 2549.cc:  No.2549 Paint Eggs - yukicoder
 */

#include<cstdio>
#include<vector>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 200000;
const int MAX_M = 200000;
const long long LINF = 1LL << 62;

/* typedef */

typedef long long ll;
typedef vector<int> vi;

/* global variables */

/* subroutines */

int cs[MAX_N], as[MAX_M];
vi cvs[MAX_M];

/* main */

int main() {
  int n, m, k;
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 0; i < n; i++) scanf("%d", cs + i), cs[i]--;
  for (int i = 0; i < m; i++) scanf("%d", as + i);

  for (int i = 0; i < n; i++) cvs[cs[i]].push_back(i);

  ll mins = LINF;
  for (int i = 0; i < n; i++) {
    vi &cv = cvs[i];
    int l = cv.size();
    for (int i = 0, j = 0; i < l; i++) {
      while (j < l && cv[i] + k > cv[j]) j++;
      ll s = (ll)(k - (j - i)) * as[i];
      mins = min(mins, s);
    }
  }

  printf("%lld\n", mins);

  return 0;
}