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 = [int(x) for x in input().split()]

da = {2:0,3:0,5:0}
db = {2:0,3:0,5:0}

while a%2 == 0 or a%3 == 0 or a%5 == 0:
    if a%2 == 0:
        da[2]+=1
        a = a/2
        continue
    if a%3 == 0:
        da[3]+=1
        a = a/3
        continue
    if a%5 == 0:
        da[5]+=1
        a = a/5
        continue

while b%2 == 0 or b%3 == 0 or b%5 == 0:
    if b%2 == 0:
        db[2]+=1
        b = b/2
        continue
    if b%3 == 0:
        db[3]+=1
        b = b/3
        continue
    if b%5 == 0:
        db[5]+=1
        b = b/5
        continue

if a != b:
    print (-1)
else:
    ans = abs(da[2]-db[2])+abs(da[3]-db[3])+abs(da[5]-db[5])
    print (ans)