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>).
def div(a, i):
    re = 0
    while a % i == 0:
        a //= i
        re += 1
    return re


a, b = map(int, input().split())
a2 = div(a, 2)
a3 = div(a, 3)
a5 = div(a, 5)
x = a // pow(2, a2)
x //= pow(3, a3)
x //= pow(5, a5)

b2 = div(b, 2)
b3 = div(b, 3)
b5 = div(b, 5)
y = b // pow(2, b2)
y //= pow(3, b3)
y //= pow(5, b5)

if x != y:
    print(-1)
else:
    print(abs(a2-b2) + abs(a3-b3) + abs(a5-b5))

