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_d = [0]*4
b_d = [0]*4


div = 2

while div <= 5:
    if div == 4:
        div += 1
        continue
    if a % div == 0:
        a_d[div-2] += 1
        a //= div
    else:
        div += 1
    
div = 2

while div <= 5:
    if div == 4:
        div += 1
        continue
    if b % div == 0:
        b_d[div-2] += 1
        b //= div
    else:
        div += 1

if a != b:
    print(-1)
else:
    print(sum(abs(a_d[i] - b_d[i]) for i in range(4)))