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 math

def solve(n, m):
    if n == m: return 0
    dp = [[0 for _ in range(m+1)] for _ in range(n+1)]

    for i in range(n+1):
        for j in range(m+1):
            if i == j:
                dp[i][j] = 0
                continue

            if i > j:
                op1, op2, op3 = math.inf, math.inf, math.inf

                if i %2 == 0: op1 = dp[i//2][j]

                if i%3 == 0: op2 = dp[i//3][j]

                if i%5 == 0: op3 = dp[i//5][j]

                res = min(op1, op2, op3)

                dp[i][j] = 1+ res

            else:
                op1, op2, op3 = math.inf, math.inf, math.inf

                if j %2 == 0: op1 = dp[i][j//2]

                if j%3 == 0: op2 = dp[i][j//3]

                if j%5 == 0: op3 = dp[i][j//5]

                res = min(op1, op2, op3)

                dp[i][j] = 1+ res
    
    res = dp[n][m]

    if res == math.inf: return -1

    return res


n, m = map(int, input().split())
print(solve(n, m))