Two little greedy bears have found two pieces of cheese in the forest of weight *a* and *b* grams, correspondingly. The bears are so greedy that they are ready to fight for the larger piece. That's where the fox comes in and starts the dialog: "Little bears, wait a little, I want to make your pieces equal" "Come off it fox, how are you going to do that?", the curious bears asked. "It's easy", said the fox. "If the mass of a certain piece is divisible by two, then I can eat exactly a half of the piece. If the mass of a certain piece is divisible by three, then I can eat exactly two-thirds, and if the mass is divisible by five, then I can eat four-fifths. I'll eat a little here and there and make the pieces equal". 

The little bears realize that the fox's proposal contains a catch. But at the same time they realize that they can not make the two pieces equal themselves. So they agreed to her proposal, but on one condition: the fox should make the pieces equal as quickly as possible. Find the minimum number of operations the fox needs to make pieces equal.
The first line contains two space-separated integers *a* and *b* (1 ≤ *a*, *b* ≤ 10<sup class="upper-index">9</sup>).
a, b = map(int, input().split())


def gcd(a, b):
    while a != b:
        if a > b:
            a -= b
        else:
            b -= a
    return a


def f(d):
    y = 0
    while d > 1:
        if d % 2 == 0:
            d /= 2
            y += 1
        elif d % 3 == 0:
            d /= 3
            y += 1
        elif d % 5 == 0:
            d /= 5
            y += 1
        else:
            return 0
    return y


x = gcd(a, b)
if a == b:
    print('0')
elif x % 2 != 0 and x % 3 != 0 and x % 5 != 0:
    print('-1')
else:
    a2 = a / x
    b2 = b / x

    ai = f(a2)
    bi = f(b2)
    if ai == 0 or bi == 0:
        print("-1")
    else:
        print(ai + bi)
