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>).
a, b = map(int, input().split())
if a != b:
    opr2 = opr3 = opr5 = 0

    while a % 2 == 0:
        a //= 2
        opr2 += 1
    while a % 3 == 0:
        a //= 3
        opr3 += 1
    while a % 5 == 0:
        a //= 5
        opr5 += 1

    while b % 2 == 0:
        b //= 2
        opr2 -= 1
    while b % 3 == 0:
        b //= 3
        opr3 -= 1
    while b % 5 == 0:
        b //= 5
        opr5 -= 1

    if a == b:
        print(abs(opr2) + abs(opr3) + abs(opr5))
    else:
        print(-1)

else:
    print(0)