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>).
# 1/2  2/3  4/5
from sys import stdin
import math


def ssolve():
    a, b = (map(int, stdin.readline().split()))
    l=[0,0,0]
    while a % 5 == 0:
        a = a//5
        l[0]+=1
        
    while a % 3 == 0:
        a=a//3
        l[1]+=1
    while a % 2 == 0:
        a=a//2
        l[2]+=1
    if a!=1:
      return -1



    while b % 5 == 0:
        b = b//5
        l[0]-=1
    while b % 3 == 0:
        b=b//3
        l[1]-=1
    while b % 2 == 0:
        b=b//2
        l[2]-=1
    if b!=1:
        return -1
    tot=0
    for i in l:
        tot+=abs(i)
    return tot
print(ssolve())