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())

x1,x2,x3 = 0,0,0
y1,y2,y3 = 0,0,0

def div(n,m):
	ans=0
	while n%m==0 :
		ans+=1
		n//=m
	return [ans,n]

x1,a = div(a,2)
x2,a = div(a,3)
x3,a = div(a,5)

y1,b = div(b,2)
y2,b = div(b,3)
y3,b = div(b,5)

if a!=b :
	print(-1)
else:
	print(abs(x1-y1)+abs(x2-y2)+abs(x3-y3))