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>).
t=1
for _ in range(t):
    inp=list(map(int,input().split()))
    a,b=inp[0], inp[1]
    a2=0
    a3=0
    a5=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
    b2=0
    b3=0
    b5=0
    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)
    else:
        ans=abs(a2-b2)+abs(a3-b3)+abs(a5-b5)
        print(ans)