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>).
def prime(n):
    a=0
    b=0
    c=0
    while n%2==0: 
        n/=2
        a+=1
    while n%3==0:
        n/=3
        b+=1
    while n%5==0:
        n/=5
        c+=1
    return n,a,b,c
a,b=map(int,input().split())
if a==b:
    print(0)
    exit()
x,a1,a2,a3=prime(a)
y,b1,b2,b3=prime(a)
if x!=y:
    print(-1)
else:
    print(abs(a1-b1)+abs(a2-b2)+abs(a3-b3))