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())
a_fact, b_fact = [], []
while a % 2 == 0:
    a_fact.append(2)
    a //= 2
while a % 3 == 0:
    a_fact.append(3)
    a //= 3
while a % 5 == 0:
    a_fact.append(5)
    a //= 5
while b % 2 == 0:
    b_fact.append(2)
    b //= 2
while b % 3 == 0:
    b_fact.append(3)
    b //= 3
while b % 5 == 0:
    b_fact.append(5)
    b //= 5
if a != b:
    print(-1)
    exit(0)
else:
    ans = abs(a_fact.count(2) - b_fact.count(2)) + abs(a_fact.count(3) - b_fact.count(3)) + abs(a_fact.count(5) - b_fact.count(5))
    print(ans)