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>).
def reduceToSmallest(a,table) :
    while True :
        if a%2 == 0 :
            table[0] += 1
            a = a//2
        elif a%3 == 0 :
            table[1] += 1
            a = a//3
        elif a&5 == 0 :
            table[2] += 1
            a = a//5
        else :
            break
    return a
        
    
    



a,b = list(map(int,input().split()))
if a == b :
    print(0)   
else :
    table = [0]*3
    table2 = [0]*3
    
    smallA = reduceToSmallest(a,table)
    smallB = reduceToSmallest(b,table2)
    
    if smallA != smallB :
        print (-1)
    else :
        print (abs(table[0] - table2[0]) + abs(table[1] - table2[1]) + abs(table[2] - table2[2]))
    
    