import java.util.Arrays;
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int t = sc.nextInt();
		int x = sc.nextInt();
		int a = sc.nextInt();
		int y = sc.nextInt();
		int b = sc.nextInt();
		sc.close();

		int m = 40000000;
		int m2 = 20000000;
		t += m2;
		long[] d = new long[m];
		Arrays.fill(d, Long.MAX_VALUE);
		d[m2] = 0;
		PriorityQueue<Node> que = new PriorityQueue<Node>();
		Node first = new Node(m2, 0);
		que.add(first);

		int[] dx = {1, a, -b};
		int[] dd = {1, x, y};
		while (!que.isEmpty()) {
			Node cur = que.poll();
			if (cur.d > d[cur.v]) {
				continue;
			}
			if (cur.v == t) {
				System.out.println(d[cur.v]);
				return;
			}
			for (int i = 0; i < 3; i++) {
				int next = cur.v + dx[i];
				if (next < 0 || m <= next) {
					continue;
				}
				long alt = d[cur.v] + dd[i];
				if (alt < d[next]) {
					d[next] = alt;
					que.add(new Node(next, alt));
				}
			}
		}
	}

	static class Hen {
		int v, c;

		public Hen(int v, int c) {
			this.v = v;
			this.c = c;
		}
	}

	static class Node implements Comparable<Node> {
		int v;
		long d;

		public Node(int v, long d) {
			this.v = v;
			this.d = d;
		}

		public int compareTo(Node o) {
			return Long.compare(d, o.d);
		}
	}
}