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 bisect import bisect_right
import math
from queue import PriorityQueue
from sys import stdin, stdout
import collections
input, print = stdin.readline, stdout.write


def str_input():
    s = input()
    return s[:len(s)-1]


def char_list_input():
    s = input()
    return list(s[:len(s)-1])


def list_input(type):
    return list(map(type, input().split()))


def multi_input():
    return map(int, input().split())


def main():
    a, b = multi_input()
    d = math.gcd(a,b)
    a = a//d
    b = b//d
    ans = 0
    while a%2==0:
        ans += 1
        a//=2
    while a%3==0:
        ans += 1
        a//=3
    while a%5==0:
        ans += 1
        a//=5
    while b%2==0:
        ans += 1
        b//=2
    while b%3==0:
        ans += 1
        b//=3
    while b%5==0:
        ans += 1
        b//=5
    if a>1 or b>1:
        ans = -1
    print(f"{ans}\n")





if __name__ == "__main__":
    main()
