#include <bits/stdc++.h>
using namespace std;
const long long ool = 1e18 + 9;
const int oo = 1e9 + 9, base = 1e9 + 7;
const double eps = 1e-7;
const int N = 2e6 + 6;
int n, m;
int a[N], pos[N], K;
long long X, Y;
void solve() {
  cin >> n >> m;
  cin >> X >> K >> Y;
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
    pos[a[i]] = i;
  }
  int last = 0;
  bool bad = 0;
  vector<int> vec;
  vec.emplace_back(0);
  for (int i = 1; i <= m; ++i) {
    int x;
    cin >> x;
    if (pos[x] < last)
      bad = 1;
    else {
      last = pos[x];
      vec.emplace_back(last);
    }
  }
  vec.emplace_back(n + 1);
  if (bad) {
    cout << "-1\n";
    return;
  }
  long long ans = 0;
  for (int i = 1; i <= (int)vec.size() - 1; ++i) {
    int l = vec[i - 1], r = vec[i];
    int mx = max(a[l], a[r]);
    int cnt = 0;
    for (int i = l + 1; i <= r - 1; ++i) {
      if (a[i] > mx) ++cnt;
    }
    if (cnt > 0 && (r - l - 1) < K) {
      cout << "-1\n";
      return;
    }
    if (X < Y * K) {
      ans += X * ((r - l - 1) / K) + Y * ((r - l - 1) % K);
    } else {
      if (!cnt) {
        ans += (r - l - 1) * Y;
      } else {
        ans += (r - l - 1 - K) * Y + X;
      }
    }
  }
  cout << ans << "\n";
}
void clear() {}
int main() {
  ios_base ::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int T = 1;
  while (T--) {
    solve();
    clear();
  }
  return 0;
}
