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>).
def dividir(n):
  count = [0, 0, 0]
  while (n%2==0):
    count[0] = count[0]+1
    n = n/2
  while (n%3==0):
    count[1] = count[1]+1
    n = n/3
  while (n%5==0):
      count[2] = count[2]+1
      n = n/5
  return (count, n)

nums = input()
ab = nums.split(' ')
a = int(ab[0])
b = int(ab[1])

A = dividir(a)
B = dividir(b)

if (A[1] != B[1]):
  print("-1\n")
else:
  cuentaA = A[0]
  cuentaB = B[0]
  res = abs(cuentaA[0]-cuentaB[0]) + abs(cuentaA[1]-cuentaB[1]) + abs(cuentaA[2]-cuentaB[2])
  print(str(res) + "\n")
   				   	 	  		 	  	 		  	 		