import java.util.Comparator;
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		try (Scanner sc = new Scanner(System.in)) {
			int N = sc.nextInt(), A = sc.nextInt(), B = sc.nextInt(), X = sc.nextInt(), Y = sc.nextInt();
			int[] H = new int[N];
			for (int i = 0;i < N;++ i) H[i] = sc.nextInt();
			int ng = -1, ok = 1_000_000_000;
			while(ok - ng > 1) {
				int mid = ok + ng >> 1;
				PriorityQueue<Integer> pq = new PriorityQueue<>(Comparator.reverseOrder());
				for (int i : H) pq.add(i - mid);
				for (int i = 0;i < A;++ i) pq.add(pq.poll() - X);
				long sum = 0;
				while(!pq.isEmpty()) {
					if (pq.peek() > 0) sum += pq.poll();
					else break;
				}
				if ((long)B * Y >= sum) ok = mid;
				else ng = mid;
			}
			System.out.println(ok);
		}
	}
}