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 sys;import copy;
import math;
def get_ints(): return map(int, sys.stdin.readline().strip().split())
def get_array(): return list(map(int, sys.stdin.readline().strip().split()))
def get_string(): return sys.stdin.readline().strip()
 
#t = int(input());
t=1;
for test in range(t):
    a,b = get_ints();
    a2=0;a3=0;a5=0;
    b2=0;b3=0;b5=0;
    while(a%2==0):
        a2+=1;
        a=a//2;
    while(a%3==0):
        a3+=1;
        a=a//3;
    while(a%5==0):
        a5+=1;
        a=a//5;
    while(b%2==0):
        b2+=1;
        b=b//2;
    while(b%3==0):
        b3+=1;
        b=b//3;
    while(b%5==0):
        b5+=1;
        b=b//5;
    if(a!=b):
        print(-1);
        continue;
    else:
        print(abs(a2-b2)+abs(b3-a3)+abs(a5-b5));
        
