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 sys


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


if( a == b):
	print(0)
	sys.exit()

if(a % 2 == 0 and b % 2 == 0):
	print(-1)
	sys.exit()


else:
	i = 0
	while(a!=b):
		if(a % 2 == 0):
			eat = a * 1 / 2 
			a = a - eat
		if (a % 3 == 0):
			eat = a * 2 / 3 
			a = a - eat
		if (a % 5 == 0):
			eat = a * 4 / 5
			a = a - eat

		if(b % 2 == 0):
			eat = b * 1 / 2 
			b = b - eat
		if (b % 3 == 0):
			eat = b * 2 / 3 
			b = b - eat
		if (b % 5 == 0):
			eat = b * 4 / 5
			b = b - eat
		i = i + 1
	print(i + 1)