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

def count_operations(a, b):
    gcd_value = gcd(a, b)
    a //= gcd_value
    b //= gcd_value
    factors = [2, 3, 5]
    for factor in factors:
        while a % factor == 0:
            a //= factor
        while b % factor == 0:
            b //= factor
    if a == 1 and b == 1:
        operations = 0
        for factor in factors:
            while gcd_value % factor == 0:
                gcd_value //= factor
                operations += 1
        return operations
    else:
        return -1

a, b = map(int, input().split())
print(count_operations(a, b))
 		   	   	   	  			 	   			  	