t = int(input())
x,a = map(int,input().split())
y,b = map(int,input().split())
import heapq
inf = 10 ** 15
r = max(2*a,2*t)
l = min(-b,t*2)
vis = [inf] * (1 + r - l)
q = [(0,0)]
while q:
    cost,node = heapq.heappop(q)
    if vis[node] <= cost:continue
    vis[node] = cost
    if l <= node + a <= r:
        if vis[node+a] == inf:
            heapq.heappush(q,(cost+x,node + a))
    if l <= node + 1 <= r:
        if vis[node+1] == inf:
            heapq.heappush(q,(cost+1,node + 1))
    if l <= node - b <= r:
        if vis[node-b] == inf:
            heapq.heappush(q,(cost+y,node - b))
#     print(q)
print(vis[t])