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>).
from collections import Counter
a,b = map(int, input().split())

def get_primes(num):
    primes = []
    prod = 1
    cur = num
    for i in range(2,int(num**0.5)+1):
        while cur % i == 0:
            primes.append(i)
            cur //= i
            prod *= i
    if prod < num:
        primes.append(num//prod)
    return primes

ap = Counter(get_primes(a))
bp = Counter(get_primes(b))
both = ap & bp
cp = (ap-both) + (bp-both)

if not set(cp).issubset({2,3,5}):
    print(-1)
    exit()

print(sum(cp.values()))
