#include <bits/stdc++.h>
using namespace std;
const int N = 200009;
int n, m, a[N], b[N], k, x, y, z, flag;
long long ans, sum, res;
int main() {
  scanf("%d%d", &n, &m);
  scanf("%d%d%d", &x, &k, &y);
  for (int i = 1; i <= n; ++i) scanf("%d", &a[i]);
  for (int i = 1; i <= m; ++i) scanf("%d", &b[i]);
  int len = 0, now = 1, maxn = 0;
  for (int i = 1; i <= m + 1; ++i) {
    while (a[now] != b[i] && now <= n) ++len, maxn = max(maxn, a[now++]);
    if (now == n + 2) {
      puts("-1");
      return 0;
    }
    if (maxn > a[now - len - 1] && maxn > a[now]) {
      if (len < k) {
        puts("-1");
        return 0;
      } else {
        len -= k;
        ans += x;
      }
    }
    if (len > 0) {
      res = 1e16;
      for (int j = 0; j * k <= len; ++j)
        res = min(res, 1LL * j * x + 1LL * y * (len - j * k));
      ans += res;
    }
    ++now, len = maxn = 0;
  }
  printf("%lld\n", ans);
  return 0;
}
