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>).
a,b=map(int,input().split())
p,q=a,b
aa=[0,0,0]
bb=[0,0,0]
flag,flags=0,0
while True:
    flag=0
    if(a==1):
        flag=2
        break
    if(a%2==0):
        aa[0]+=1
        a//=2
        flag=1
    elif(a%3==0):
        aa[1]+=1
        a//=3
        flag=1
    elif(a%5==0):
        aa[2]+=1
        a//=5
        flag=1
    if(flag==0):
        flag=3
        break
while True:
    flags=0
    if(b==1):
        flags=22
        break
    if(b%2==0):
        bb[0]+=1
        b//=2
        flags=1
    elif(b%3==0):
        bb[1]+=1
        b//=3
        flags=1
    elif(b%5==0):
        bb[2]+=1
        b//=5
        flags=1
    if(flags==0):
        flags=33
        break

if(p==q):
    print(0)
elif(flag==2 and flags==22):
    print(max(aa[0],bb[0])-min(aa[0],bb[0])+max(aa[1],bb[1])-min(aa[1],bb[1])+max(aa[2],bb[2])-min(aa[2],bb[2]))
else:
    print(-1)