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())
def div(c):
    a2,a3,a5 = 0,0,0
    while(c %2 == 0):
        c//=2
        a2+=1
    while(c %3 == 0):
        c//=3
        a3+=1
    while(c%5 == 0):
        c//=5
        a5+=1
    return c,a2,a3,a5
    
def sol(a,b):
    c,a2,a3,a5 = div(a)
    d,b2,b3,b5 = div(b)
    if(c!=d):
        return -1
    return abs(a2-b2)+abs(a3-b3)+abs(a5-b5)
print(sol(a,b))