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 math
def generate1(n):
    mydict={2:0,3:0,5:0}
    first=True
    while n%2==0:
        if first:
            mydict[2]=0
            first=False
        mydict[2]+=1
        n//=2
    first=True
    for i in range(3,int(math.sqrt(n))+1,2):
        first=True
        while n%i==0:
            if first:
                first=False
                mydict[i]=0
            mydict[i]+=1
            n//=i
   
    if n>2:
        mydict[n]=0
        mydict[n]+=1
    return mydict
def generate(n):
  mydict={2:0,3:0,5:0}
  while n%2==0:
    n//=2
    mydict[2]+=1
  while n%3==0:
    n//=3
    mydict[3]+=1
  while n%5==0:
    n//=5
    mydict[5]+=1
  return n,mydict
a,b=map(int,input().split())
if a==b:
  print(0)
else:
  tmp1,mydict1=generate(a)
  tmp2,mydict2=generate(b)
  if tmp1!=tmp2:
    print(-1)
  else:
    minmove=abs(mydict1[2]-mydict2[2])+abs(mydict1[3]-mydict2[3])+abs(mydict1[5]-mydict2[5])
    print(minmove)