D = int(input())
H1 = int(input())
H2 = int(input())
H3 = int(input())

def is_kadomatsu(h1, h2, h3):
    return h1 != h3 and ((h1 < h2 and h3 < h2) or (h2 < h1 and h2 < h3))

def magic(h):
    return max(0, h-D)

def magic_until(h,t):
    i = 0
    while t <= h:
        if t == 0 and h == 0:
            return 0,float('inf')
        h = magic(h)
        i = i + 1
    return h,i

def recheck(h1, h2, h3):
    if is_kadomatsu(h1,h2,h3):
        return True,0
    else:
        m = max(h1,h3)
        n = min(h1,h3)
        h4,i = magic_until(m,h2)
        h5,j = magic_until(h2,n)
        if i < j:
            return is_kadomatsu(h4 if h1 == m else h1, h2, h4 if h3 == m else h3),i
        else:
            return is_kadomatsu(h1, h5, h3),j

def check(h1, h2, h3):
    if D == 0:
        return is_kadomatsu(h1, h2, h3),0
    elif h1 == h2 and h2 == h3 and h1 == h3:
        h1 = magic(magic(h1))
        h3 = magic(h3)
        return is_kadomatsu(h1,h2,h3),3

    elif h1 == h3 and h1 != h2 and h3 != h2:
        h1 = magic(h1)
        if is_kadomatsu(h1,h2,h3):
            return True,1
        else:
            return recheck(h1,h2,h3)
    else:
        return recheck(h1,h2,h3)

found,i = check(H1,H2,H3)
if found:
    print(i)
else:
    print(-1)