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>).
import math
from collections import Counter
def primeFactors(n):
    a = []
    while n % 2 == 0:
        a.append(2)
        n = n // 2
    for i in range(3, int(math.sqrt(n)) + 1, 2):
        while n % i == 0:
            a.append(i)
            n = n // i
    if n > 2:
        a.append(n)
    return a

a,b = list(map(int,input().split()))
hcf = math.gcd(a,b)
if a == b:
    print(0)
elif hcf == 1:
    print(-1)
else:
    a//=hcf
    b//=hcf
    a = Counter(primeFactors(a))
    b = Counter(primeFactors(b))
    output = 0
    f = 0
    for i in a:
        if i in [2,3,5]:
            output+=a[i]
        else:
            f = 1
            break
    if f==0:
        for i in b:
            if i in [2,3,5]:
                output+=b[i]
            else:
                f = 1
                break
    if f == 1:
        print(-1)
    else:
        print(output)




