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>).
from sys import stdin,stdout
input=stdin.readline
def print(*args, end='\n', sep=' ') -> None:
    stdout.write(sep.join(map(str, args)) + end)
n,m=map(int,input().split()) ; ans=0

while n!=m:
    if n>m:
        if n%2==0:
            n//=2
        elif n%3==0:
            n//=3
        elif n%5==0:
            n//=5
        else:
            print(-1) ; break
    else:
        if m%2==0:
            m//=2
        elif m%3==0:
            m//=3
        elif m%5==0:
            m//=5
        else:
            print(-1) ; break
    ans+=1
else:
    print(ans)