t = int(input())
x, a = map(int, input().split())
y, b = map(int, input().split())

if t < 0:
    t = abs(t)
    q = (t + b - 1) // b
    ans = q * y
    r = q * b - t
    q, rr = divmod(r, a)
    ans += min((q - (rr != 0)) * x + (a - rr) % a, r)
else:
    q, r = divmod(t, a)
    ans = q * x + r
    q += 1
    res = q * x
    r = q * a - t
    q, rr = divmod(r, b)
    res += (q + (rr != 0)) * y + (b - rr) % b
    ans = min(ans, res)
print(ans)