#include <bits/stdc++.h>
using namespace std;
long long a[200005], pos[200005];
long long n, m, x, k, y, ans = 0, flag = 1;
long long calc(long long i, long long j) {
  long long mana = 0, Max = -10e17;
  for (long long p = i + 1; p < j; ++p) {
    Max = max(Max, a[p]);
  }
  if (j - i - 1 < k) {
    if (Max > max(a[i], a[j])) {
      flag = 0;
    }
    mana = y * (j - i - 1);
  } else {
    if (x < y * k) {
      mana = ((j - i - 1) / k) * x + ((j - i - 1) % k) * y;
    } else {
      if (Max > max(a[i], a[j])) {
        mana = x + (j - i - 1 - k) * y;
      } else {
        mana = (j - i - 1) * y;
      }
    }
  }
  return mana;
}
int main() {
  long long i, prev_pos = 0;
  scanf("%lld%lld%lld%lld%lld", &n, &m, &x, &k, &y);
  for (i = 1; i <= n; ++i) {
    scanf("%lld", &a[i]);
    pos[a[i]] = i;
  }
  a[n + 1] = 0;
  for (i = 1; i <= m; ++i) {
    long long val;
    scanf("%lld", &val);
    if (pos[val] < prev_pos) {
      flag = 0;
    }
    ans += calc(prev_pos, pos[val]);
    prev_pos = pos[val];
  }
  ans += calc(prev_pos, n + 1);
  if (flag) {
    printf("%lld", ans);
  } else {
    printf("-1");
  }
  return 0;
}
