#include <bits/stdc++.h>
using namespace std;
long long int M = 1000000007;
int main() {
  long long int n, m;
  cin >> n >> m;
  long long int x, k, y;
  cin >> x >> k >> y;
  long long int arr[n + 2];
  for (long long int i = 1; i <= n; i++) cin >> arr[i];
  arr[0] = arr[n + 1] = 0;
  long long int tr[m + 2];
  tr[0] = 0;
  tr[m + 1] = 0;
  for (long long int i = 1; i <= m; i++) cin >> tr[i];
  long long int ind = 1;
  long long int ans = 0;
  long long int cc = 0;
  for (long long int i = 1; i <= m + 1; i++) {
    if (ind > n + 1) {
      cc = 1;
      break;
    }
    long long int ch = max(tr[i - 1], tr[i]);
    long long int sm = 0, gr = 0;
    while (ind <= n + 1) {
      if (arr[ind] == tr[i]) {
        ind++;
        break;
      }
      if (arr[ind] < ch)
        sm++;
      else
        gr++;
      ind++;
    }
    long long int range = gr + sm;
    if (gr == 0) {
      if (x <= y * k) {
        ans += (range % k) * y + (range / k) * x;
      } else {
        ans += range * y;
      }
    } else {
      if (range < k) {
        cc = 1;
        break;
      } else {
        if (x <= y * k) {
          ans += (range % k) * y + (range / k) * x;
        } else {
          ans += (range - k) * y + x;
        }
      }
    }
  }
  if (cc)
    cout << -1 << endl;
  else
    cout << ans << endl;
  return 0;
}
