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>).
num1, num2 = [int(i) for i in input().split()]
opr = 0
arr_1 = []
arr_2 = []
a = 0
b = 0
c = 0
check = 1 
while num1 != 1:
	if num1 % 2 == 0:
		a += 1
		num1 /= 2
	elif num1 % 3 == 0:
		b += 1
		num1 /= 3
	elif num1 % 5 == 0:
		c += 1
		num1 /= 5
	else:
		check = 0
		break

while num2 != 1 and check:
	if num2 % 2 == 0:
		a -= 1
		num2 /= 2
	elif num2 % 3 == 0:
		b -= 1
		num2 /= 3
	elif num2 % 5 == 0:
		c -= 1
		num2 /= 5
	else:
		check = 0
if check :
	print(abs(a) +abs(b)+ abs(c))
else:
	print(-1)
