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 = list(map(int,input().split()))
q = [(a,0)]
mapper_a = {}
mapper_b = {}
while q!=[]:
    cur,d = q[0]
    q.pop(0)
    mapper_a[cur] = d
    for i in [2,3,5]:
        if cur%i==0:
            if cur//i not in mapper_a:
                q.append((cur//i,d+1))
q = [(b,0)]
while q!=[]:
    cur,d = q[0]
    q.pop(0)
    mapper_b[cur] = d
    for i in [2,3,5]:
        if cur%i==0:
            if cur//i not in mapper_b:
                q.append((cur//i,d+1))
ans = 10**18
for i in mapper_a:
    if i in mapper_b:
        ans = min(ans,mapper_a[i]+mapper_b[i])
if ans==10**18:
    print(-1)
else:
    print(ans)