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


def prime_factors(q):
    factors = []
    i = 2
    while i <= q:
        if q % i == 0:
            factors.append(i)
            q = q // i
        else:
            i += 1
    return factors


a, b = [int(x) for x in input().split()]

fac_a = prime_factors(a)
fac_b = prime_factors(b)

i = 0
while i < len(fac_a) and i < len(fac_b):
    if fac_a[i] in fac_b:
        fac_b.remove(fac_a[i])
        fac_a.pop(i)
    else:
        i += 1

for f in fac_a:
    if f not in [2, 3, 5]:
        print(-1)
        quit()
        
for f in fac_b:
    if f not in [2, 3, 5]:
        print(-1)
        quit()

print(len(fac_a) + len(fac_b))