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 gcd(a, b):
    while a > 0 and b > 0:
        if a >= b:
            a %= b
        else:
            b %= a
    return max(a, b)

def razl(n):
    res = []
    for i in range(2, int(n**(1/2)) + 1, 1):
        while n % i == 0:
            res.append(i)
            n //= i
    if n != 1:
        res.append(n)
    return res

def main():
    a, b = list(map(int, input().split()))
    target = gcd(a, b)
    target_r = razl(target)
    a_r = razl(a)
    b_r = razl(b)
    a_count = {i: 0 for i in a_r}
    b_count = {i: 0 for i in b_r}
    target_count = {i: 0 for i in target_r}
    a_count[2], a_count[3], a_count[5] = 0, 0, 0
    b_count[2], b_count[3], b_count[5] = 0, 0, 0
    target_count[2], target_count[3], target_count[5] = 0, 0, 0

    for i in a_r:
        a_count[i] += 1
    for i in b_r:
        b_count[i] += 1
    for i in target_r:
        target_count[i] += 1

    ans = 0
    for i in [2, 3, 5]:
        while a_count[i] > target_count[i]:
            ans += 1
            a //= i
            a_count[i] -= 1


    for i in [2, 3, 5]:
        while b_count[i] > target_count[i]:
            ans += 1
            b //= i
            b_count[i] -= 1

    if b == target and a == target:
        print(ans)
    else:
        print(-1)

if __name__ == "__main__":
    main()