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())
p, q = a, b
aa = [0, 0, 0]
bb = [0, 0, 0]
flag, flags = 0, 0
while True:
    flag = 0
    if (a == 1):
        flag = 2
        break
    if (a % 2 == 0):
        aa[0] += 1
        a //= 2
        flag = 1
    elif (a % 3 == 0):
        aa[1] += 1
        a //= 3
        flag = 1
    elif (a % 5 == 0):
        aa[2] += 1
        a //= 5
        flag = 1
    if (flag == 0):
        flag = 3
        break
while True:
    flags = 0
    if (b == 1):
        flags = 22
        break
    if (b % 2 == 0):
        bb[0] += 1
        b //= 2
        flags = 1
    elif (b % 3 == 0):
        bb[1] += 1
        b //= 3
        flags = 1
    elif (b % 5 == 0):
        bb[2] += 1
        b //= 5
        flags = 1
    if (flags == 0):
        flags = 33
        break

if (p == q):
    print(0)
elif (a==b):
    print(max(aa[0], bb[0]) - min(aa[0], bb[0]) + max(aa[1], bb[1]) - min(aa[1], bb[1]) + max(aa[2], bb[2]) - min(aa[2],
                                                                                                                  bb[
                                                                                                                      2]))
else:
    print(-1)