package chelper;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import io.InputReader;
import io.OutputWriter;
import misc.Couple;
import misc.Pair;
import misc.SimpleSavingChelperSolution;


public class K extends SimpleSavingChelperSolution {

  public void solve(int testNumber, InputReader in, OutputWriter out) {
    wrapSolve(testNumber, in, out);
  }

  @Override
  public void solve(int testNumber) {
    int n = in.nextInt();
    int a = in.nextInt();
    int b = in.nextInt();
    int k = in.nextInt();
    int f = in.nextInt();

    Map<String, Integer> nameToId = new HashMap<>();

    List<Couple<Integer>> trips = new ArrayList<>();

    Map<Couple<Integer>, Integer> costs = new HashMap<>();

    int prev = -1;

    for (int i = 0; i < n; i++) {
      String s1 = in.nextString();
      String s2 = in.nextString();

      if (!nameToId.containsKey(s1)) {
        nameToId.put(s1, nameToId.size());
      }
      if (!nameToId.containsKey(s2)) {
        nameToId.put(s2, nameToId.size());
      }

      int id1 = nameToId.get(s1);
      int id2 = nameToId.get(s2);

      Couple<Integer> couple = new Couple<>(id1, id2);
      trips.add(couple);

      int cost = a;

      if (prev == id1) {
        cost = b;
      }
      prev = id2;

      if (id1 > id2) {
        int t = id1;
        id1 = id2;
        id2 = t;
      }
      couple = new Couple<>(id1, id2);

      costs.putIfAbsent(couple, 0);
      costs.put(couple, costs.get(couple) + cost);
    }

    List<Pair<Couple<Integer>, Integer>> coupleCosts = new ArrayList<>();

    int total = 0;

    for (Map.Entry<Couple<Integer>, Integer> entry : costs.entrySet()) {
      coupleCosts.add(new Pair<>(entry.getKey(), entry.getValue()));
      total += entry.getValue();
    }

    coupleCosts.sort(new Comparator<Pair<Couple<Integer>, Integer>>() {
      @Override
      public int compare(Pair<Couple<Integer>, Integer> o1, Pair<Couple<Integer>, Integer> o2) {
        return -Integer.compare(o1.second, o2.second);
      }
    });

    for (int i = 0; i < Math.min(k, coupleCosts.size()); i++) {
      int orig = coupleCosts.get(i).second;
      if (orig > f) {
        total += f - orig;
      } else {
        break;
      }
    }

    out.println(total);
  }
}