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())
x = [0,0,0]
y = [0,0,0]
b1 = True
b2 = True
if a == b:
    print(0)
else:
    while a!= 1 or b!= 1:
        if a != 1:
            if a % 2 ==0:
                a = a / 2
                x[0] += 1
            elif a % 3 ==0:
                a = a /3
                x[1] += 1
            elif a % 5 ==0:
                a = a / 5
                x[2] += 1
            else:
                b1 = False
                print(-1)
                break
        if b != 1:
            if b % 2 ==0:
                b = b / 2
                y[0] += 1
            elif b % 3 ==0:
                b = b /3
                y[1] += 1
            elif b % 5 ==0:
                b = b / 5
                y[2] += 1
            else:
                b2 = False
                print(-1)
                break
    if b1 and b2:
        print(abs(x[0]-y[0]) + abs(x[1]-y[1]) + abs(x[2]-y[2]))
            
