#include <bits/stdc++.h>
using namespace std;
long long n, m, x, k, y, maks, tmp, a[200005], b[200005], pos[200005],
    dp[2][200005], ans;
bool f;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m >> x >> k >> y;
  for (int i = 1; i <= n; i++) {
    dp[0][i] = i * y;
    if (i >= k) {
      if (x <= k * y) {
        maks = i / k;
        dp[1][i] = maks * x + (i - maks * k) * y;
      } else {
        dp[1][i] = x + (i - 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];
  }
  for (int i = 0; i < m; i++) {
    if (pos[b[i]] < pos[b[i + 1]]) {
      tmp = pos[b[i + 1]] - pos[b[i]] - 1, maks = 0;
      for (int j = pos[b[i]] + 1; j < pos[b[i + 1]]; j++) {
        maks = max(a[j], maks);
      }
      if (tmp < k) {
        if (maks > max(b[i], b[i + 1])) {
          f = true;
          break;
        }
        ans += dp[0][tmp];
      } else {
        if (maks > max(b[i], b[i + 1])) {
          ans += dp[1][tmp];
        } else {
          ans += min(dp[1][tmp], dp[0][tmp]);
        }
      }
    } else {
      f = true;
      break;
    }
  }
  maks = 0, tmp = n - pos[b[m]];
  for (int i = pos[b[m]] + 1; i <= n; i++) {
    maks = max(maks, a[i]);
  }
  if (tmp < k) {
    if (maks > b[m]) {
      f = true;
    }
    ans += dp[0][tmp];
  } else {
    if (maks > b[m]) {
      ans += dp[1][tmp];
    } else {
      ans += min(dp[0][tmp], dp[1][tmp]);
    }
  }
  if (f) {
    cout << -1 << '\n';
  } else {
    cout << ans << '\n';
  }
}
