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>).
import math


def factorize(x):
    factors = []
    y = 1
    for i in range(2, int(math.sqrt(x) + 1)):
        while x % i == 0:
            factors.append(i)
            x //= i
            if i not in [2, 3, 5]:
                y *= i

    if x != 1:
        factors.append(x)
        if x not in [2, 3, 5]:
            y *= x

    return factors, y


a, b = map(int, input().split())

factorsa, x = factorize(a)
factorsb, y = factorize(b)

if x != y:
    print(-1)
else:
    print(abs(factorsa.count(2) - factorsb.count(2))
          + abs(factorsa.count(3) - factorsb.count(3))
          + abs(factorsa.count(5) - factorsb.count(5)))
