#include <bits/stdc++.h>
using namespace std;
long long n, m, x, k, y;
long long a[200005], b[200005];
long long pos[200005];
int main() {
  cin >> n >> m;
  cin >> x >> k >> y;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    pos[a[i]] = i;
  }
  for (int i = 1; i <= m; i++) {
    cin >> b[i];
  }
  if (m > n) {
    cout << -1;
    return 0;
  }
  for (int i = 2; i <= m; i++) {
    if (pos[b[i]] < pos[b[i - 1]]) {
      cout << -1;
      return 0;
    }
  }
  long long ans = 0;
  for (int i = 1; i <= m + 1; i++) {
    if (i == m + 1) pos[0] = n + 1;
    int dif = pos[b[i]] - pos[b[i - 1]] - 1;
    if (dif == 0) continue;
    long long maxim = 0;
    for (int j = pos[b[i - 1]] + 1; j < pos[b[i]]; j++) {
      maxim = max(maxim, a[j]);
    }
    if (max(b[i], b[i - 1]) > maxim) {
      long long cx = min(x, y * k);
      ans += cx * (dif / k) + y * (dif % k);
    } else {
      if (dif < k) {
        cout << -1;
        return 0;
      } else {
        if (y * k < x) {
          ans += (dif - k) * y + x;
        } else {
          long long cx = min(x, y * k);
          ans += cx * (dif / k) + y * (dif % k);
        }
      }
    }
  }
  cout << ans;
}
