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>).

from collections import deque
def primefac(n):
    d = deque()

    while n % 2 == 0 :
        n//=2
        d.append(n)

    while n % 3 == 0 :
        n//=3
        d.append(n)

    while n % 5 == 0 :
        n//=5
        d.append(n)


    return d
n , m = map(int,input().split())
if n == m :
    print(0)
    exit(0)

r1 = (primefac(n))
if 1 in r1 :r1.remove(1)
r2 = (primefac(m))
if 1 in r2 : r2.remove(1)
#print(r1)
#print(r2)

r3 = (set(r1).intersection(set(r2)))
if r3 == set():
    print(-1)
    exit(0)

else:
    print(len(r1) + len(r2))


