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>).
import sys


def gcd(a,b):
    if(b==0):
        return a
    else:
        return gcd(b,a%b)


a, b = input().split()
a = int(a)
b = int(b)

if (a == b):
    print(0)
    sys.exit()

if (a % 2 == 0 and b % 2 == 0):
    print(-1)
    sys.exit()

else:
    a_count = 0
    b_count = 0
    res = gcd(a, b)
    while True:
        if a <= res:
            break
        if a % 2 == 0:
            a = a // 2
            a_count = a_count + 1
            continue
        if a % 3 == 0:
            a = a // 3
            a_count = a_count + 1
            continue
        if a % 5 == 0:
            a = a // 5
            a_count = a_count + 1
            continue

    while True:
        if b <= res:
            break
        if b % 2 == 0:
            b = b // 2
            b_count = b_count + 1
            continue
        if b % 3 == 0:
            b = b // 3
            b_count = b_count + 1
            continue
        if b % 5 == 0:
            b = b // 5
            b_count = b_count + 1
            continue

    print(a_count + b_count)

'''

limit = gcd(a,b)
while True:
	i = 0
	limit = 5
	if(a % 2 == 0):
		eat = a * 1 / 2
		a = a - eat
		i = i + 1
		if a == limit:
			break
		elif(a % 3 == 0):
			eat = a * 2 / 3
			a = a - eat
			i = i + 1
			if a == limit:
				break
			elif(a % 5 == 0):
				eat = a * 4 / 5
				a = a - eat
				i = i + 1
				if a == limit:
					break
	if(a % 2 == 0):
		eat = a * 1 / 2
		a = a - eat
		i = i + 1
		if a == limit:
			break
		elif(a % 3 == 0):
			eat = a * 2 / 3
			a = a - eat
			i = i + 1
			if a == limit:
				break
			elif(a % 5 == 0):
				eat = a * 4 / 5
				a = a - eat
				i = i + 1
				if a == limit:
					break
print(i)


'''