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 nod_custom(a, b):
    a1, b1 = a, b
    while a1 != 0 and b != 0:
        if a1 > b1:
            a1 %= b1
        else:
            b1 %= a1
    return b1 + a1

a, b = map(int, input().split())
if a == b:
    print(0)
    exit(0)
ans = nod_custom(a, b)
ans1 = a // ans
ans2 = b // ans
if (ans1 % 5 != 0 and ans1 % 3 != 0 and ans1 % 2 != 0) or (ans2 % 5 != 0 and ans2 % 3 != 0 and ans2 % 2 != 0):
    print(-1)
    exit(0)
counter = 0
while ans1 != 1:
    if ans1 % 5 == 0:
        ans1 //= 5
        counter += 1
        continue
    if ans1 % 3 == 0:
        ans1 //= 3
        counter += 1
        continue
    if ans1 % 2 == 0:
        ans1 //= 2
        counter += 1
while ans2 != 1:
    if ans2 % 5 == 0:
        ans2 //= 5
        counter += 1
        continue
    if ans2 % 3 == 0:
        ans2 //= 3
        counter += 1
        continue
    if ans2 % 2 == 0:
        ans2 //= 2
        counter += 1

print(counter)