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 math import gcd,sqrt
from collections import Counter

def prim(n):
    res=[]
    while n % 2 == 0:
        res.append(2)
        n = n / 2
          
    for i in range(3,int(sqrt(n))+1,2):
          
        while n % i== 0:
            res.append(int(i))
            n = n//i
              
   
    if n > 2:
        res.append(int(n))
        
    return res
        
a,b = map(int,input().split())

gc = gcd(a,b)
r1=prim(a//gc)
r2=prim(b//gc)
d1 = Counter(r1)
d2 = Counter(r2)

if d1[2]+d1[5]+d1[3]==len(r1) and d2[2]+d2[3]+d2[5]==len(r2):
    print(len(r1)+len(r2))
    
else:
    print(-1)