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>).
# Python program to print prime factors

import math

def primeFactors(n):
    factors = []
    while n % 2 == 0:
        factors.append(2)
        n = n / 2

    for i in range(3, int(math.sqrt(n)) + 1, 2):
        while n % i == 0:
            factors.append(i)
            n = n / i

    if n > 2:
        factors.append(int(n))
    return factors

def difference(li1, li2):
    dif = [i for i in li1 + li2 if i not in li1 or i not in li2]
    return dif

a, b = map(int, input().split())
l1 = primeFactors(a)
l2 = primeFactors(b)
#print(l1)
#print(l2)
x = difference(l1,l2)
#print(x)
for i in x:
    if i > 5:
        print(-1)
        exit(0)
length=len(x)
answer=0
if length==0:
    answer = abs(len(l1) - len(l2))
else:
    answer = length
print(answer)