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 line2int(linea):
    temp = ""
    for i in linea:
        if i == " ":
            if temp != "":
                val1 = int(temp)
                temp = ""
        else:
            temp = temp + i
    val2 = int(temp)
    return (val1,val2)

(a,b) = line2int(input())
num2a = num2b = 0
num3a = num3b = 0
num5a = num5b = 0
while a%2==0:
    a = int(a/2)
    num2a = num2a + 1
while a%3==0:
    a = int(a/3)
    num3a = num3a + 1
while a%5==0:
    a = int(a/5)
    num5a = num5a + 1
while b%2==0:
    b = int(b/2)
    num2b = num2b + 1
while b%3==0:
    b = int(b/3)
    num3b = num3b + 1
while b%5==0:
    b = int(b/5)
    num5b = num5b + 1
if a==b: print(abs(num2a-num2b)+abs(num3a-num3b)+abs(num5a-num5b))
else: print(-1)
	 						 		 				 			 			 			 		