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 ; a=b=1 ; a2=a3=a5=b2=b3=b5=0
while n>1:
    if n%2==0:
        n//=2
        a2+=1
    elif n%3==0:
        n//=3
        a3+=1
    elif n%5==0:
        n//=5
        a5+=1
    else:
        a=n
        n//=n

while m>1:
    if m%2==0:
        m//=2
        b2+=1
    elif m%3==0:
        m//=3
        b3+=1
    elif m%5==0:
        m//=5
        b5+=1
    else:
        b=m
        m//=m
if b==a:
    print(abs(a2-b2)+abs(a3-b3)+abs(a5-b5))
else:
    print(-1)


