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>).
import math
import random 
from queue import Queue
import time 


def bd(n,m):

  ans=0

  while n//m==n/m :
    ans+=1 
    n//=m 
	
  return n,ans
def main(a,b):

  
  s2=bd(a,2)
  
  s3=bd(s2[0],3)

  s5=bd(s3[0],5)

  t2=bd(b,2)

  t3=bd(t2[0],3)

  t5=bd(t3[0],5)

  if s5[0]!=t5[0]:
    return -1 
  
  else:
    return abs(t2[1]-s2[1])+abs(t3[1]-s3[1])+abs(t5[1]-s5[1])

a,b=list(map(int,input().split()))
print(main(a,b))
    