#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int n, m, x, k, y;
  cin >> n >> m >> x >> k >> y;
  long long int a[n + 2];
  long long int b[m + 2];
  map<long long int, long long int> mp;
  a[0] = 0;
  a[n + 1] = n + 1;
  for (long long int i = 1; i <= n; i++) {
    cin >> a[i];
    mp[a[i]] = i;
  }
  mp[0] = 0;
  mp[n + 1] = n + 1;
  b[0] = 0;
  b[m + 1] = n + 1;
  for (long long int i = 1; i <= m; i++) {
    cin >> b[i];
  }
  bool flag = true;
  long long int ans = 0;
  for (long long int i = 1; i <= m + 1; i++) {
    long long int p = mp[b[i - 1]];
    long long int q = mp[b[i]];
    long long int diff = q - p;
    if (diff > 0) {
      long long int maxm = LLONG_MIN;
      for (long long int j = p + 1; j < q; j++) {
        maxm = max(a[j], maxm);
      }
      long long int dist = q - p - 1;
      if (dist >= k) {
        if (x < k * y) {
          ans += (dist / k) * x + (dist % k) * y;
        } else if (p != 0 && q != n + 1 && maxm < max(a[p], a[q])) {
          ans += (dist)*y;
        } else if (p == 0 && maxm < a[q]) {
          ans += (dist)*y;
        } else if (q == n + 1 && maxm < a[p]) {
          ans += (dist)*y;
        } else {
          ans += x + (dist - k) * y;
        }
      } else {
        if (p != 0 && q != n + 1 && maxm < max(a[p], a[q])) {
          ans += (dist)*y;
        } else if (p == 0 && maxm < a[q]) {
          ans += (dist)*y;
        } else if (q == n + 1 && maxm < a[p]) {
          ans += (dist)*y;
        } else {
          flag = false;
        }
      }
    } else {
      flag = false;
      break;
    }
    if (!flag) {
      break;
    }
  }
  if (flag) {
    cout << ans << endl;
  } else {
    cout << "-1" << endl;
  }
  return 0;
}
