#include <bits/stdc++.h>
using namespace std;
void OJ() {}
long long n, m, x, k, y;
long long a[200000 + 5], b[200000 + 5];
void imp() { cout << -1 << "\n", exit(0); }
long long remove(long long start, long long end) {
  if (start > end) return 0;
  long long sz = end - start + 1;
  long long maxneb = max(a[start - 1], a[end + 1]);
  long long m = *max_element(a + start, a + end + 1);
  long long a1 = (sz / k) * x + (sz % k) * y;
  if (maxneb > m) return min(a1, y * sz);
  if (sz < k) imp();
  return min(a1, (sz - k) * y + x);
}
void solve() {
  cin >> n >> m >> x >> k >> y;
  for (long long i = 1; i <= n; ++i) cin >> a[i];
  for (long long i = 1; i <= m; ++i) cin >> b[i];
  long long ans = 0;
  long long j = 1;
  for (long long i = 1; i <= m; ++i) {
    long long start = j;
    while (j <= n && a[j] != b[i]) j++;
    if (j > n) imp();
    ans += remove(start, j - 1);
    j++;
  }
  ans += remove(j, n);
  cout << ans << "\n";
}
signed main() {
  OJ();
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solve();
}
