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>).
a, b = map(int, input().split())

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