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(i) for i in input().split()]

if a == b:
    print(0)
    exit(0)
arr1 = [0, 0, 0]
arr2 = [0, 0, 0]

while a%2 == 0:
    arr1[0] += 1
    a /= 2
while a%3 == 0:
    arr1[1] += 1
    a /= 3
while a%5 == 0:
    arr1[2] += 1
    a /= 5

while b%2 == 0:
    arr2[0] += 1
    b /= 2
while b%3 == 0:
    arr2[1] += 1
    b /= 3
while b%5 == 0:
    arr2[2] += 1
    b /= 5

if a == b:
    print(abs(arr1[0] - arr2[0]) + abs(arr1[1] - arr2[1]) + abs(arr1[2] - arr2[2]))
else:
    print(-1)

