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 take_input(s):          #for integer inputs
    if s == 1:  return int(input())
    return map(int, input().split())

def div(n):
    i = 2
    while(n%i>0 and i <5):
        i += 1
    if n%i == 0:
        return n//i
    else: return n
    
a, b = take_input(2)
count = 0
if a == b:
    print(0)
    exit()

while(a>1 or b>1):
    greater = a
    if a < b:
        greater = b
        lesser = a
    else:
        lesser = b
    a = greater; b = lesser
    if div(a) != a:
        a = div(a)
        count += 1
        if a == b and a != 1:
            print(count)
            exit()
    else:
        print(-1)
        exit()
print(-1)
    