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>).
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sun Jun 14 10:28:21 2020

@author: shailesh
"""


def find_power_of(num,base):
    count = 0
    while(num%base == 0):
        num //= base
        count +=1
    return num,count



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


a,a5 = find_power_of(a,5)
b,b5 = find_power_of(b,5)

a,a3 = find_power_of(a,3)
b,b3 = find_power_of(b,3)

a,a2 = find_power_of(a,2)
b,b2 = find_power_of(b,2)


if a!=b:
    print(-1)
else:
    count = abs(a5-b5) + abs(a3-b3) + abs(a2-b2)
    print(count)