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
from collections import defaultdict
import math
from functools import reduce


VALID = {2, 3, 5}

def main() -> None:
    read = sys.stdin.readline
    a, b = (int(i) for i in read().split())
    if a == b:
        print(0)
        return
    valid_factors_a = [0] * len(VALID)
    for i, x in enumerate(VALID):
        while a % x == 0:
            a //= x
            valid_factors_a[i] += 1

    valid_factors_b = [0] * len(VALID)
    for i, x in enumerate(VALID):
        while b % x == 0:
            b //= x
            valid_factors_b[i] += 1

    if a != b:
        print(-1)
    else:
        total_cost = 0
        for i in range(len(VALID)):
            total_cost += abs(valid_factors_a[i] - valid_factors_b[i])
        print(total_cost)



if __name__ == '__main__':
    main()
