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 get_time(x):
  number = x
  count = 0
  while (number%2 == 0):
    count = count + 1
    number = number/2
  while (number%3 == 0):
    count = count + 1
    number = number/3
  while (number%5 == 0):
    count = count + 1
    number = number/5

  return [number, count]

values = input()
xy = (values.split(' '))
x = int(xy[0])
y = int(xy[1])

if (x == y):
  print(0)

else:
  x_time = get_time(x)
  y_time = get_time(y)
  
  if (x_time[0] != y_time[0]):
    print(-1)
  else:
    result = x_time[1] + y_time[2]
    print(result)
		  	  		   		 	 			  	    	