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 solve(a, b):
    contador_a = 0
    contador_b = 0
    for i, divisor in enumerate([2, 3, 5]):
        while a % divisor == 0 and a / divisor > 1:
            a /= divisor
            contador_a += 1

    for i, divisor in enumerate([2, 3, 5]):
        while b % divisor == 0 and b / divisor > 1:
            b /= divisor
            contador_b += 1

    if a == b:
        return contador_a + contador_b
    return -1


entrada = input()

a, b = map(int, entrada.split())
if a == b:
    print(0)
else:
    print(solve(a, b))

	 		 						  	  	 		 	   	 		 	