def func(x):
    f1 = (w // (a + 2 * x)) * (h // (b + 2 * x))
    f2 = (h // (a + 2 * x)) * (w // (b + 2 * x))
    f = max(f1, f2)
    return f

def search(r):
    l = 0
    while r - l > 1:
        middle = (l + r) // 2
        if func(middle) < n:
            r = middle
        else:
            l = middle
    if func(r)>=n:
        return r
    return l

n, a, b, w, h = map(int, input().split())
r = 10**50
print(search(r))