Untitled

#include <bits/stdc++.h>
using namespace std;

#define endl "\n"

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef long double ld;


void solve()
{
	int a, b;
	cin >> a >> b;
	int n2a = 0, n3a = 0, n5a = 0;
	int n2b = 0, n3b = 0, n5b = 0;

	while (a % 2 == 0)
	{
		a /= 2;
		n2a++;
	}
	while (a % 3 == 0)
	{
		a /= 3;
		n3a++;
	}
	while (a % 5 == 0)
	{
		a /= 5;
		n5a++;
	}

	while (b % 2 == 0)
	{
		b /= 2;
		n2b++;
	}
	while (b % 3 == 0)
	{
		b /= 3;
		n3b++;
	}
	while (b % 5 == 0)
	{
		b /= 5;
		n5b++;
	}

	if (a != b)
		cout << -1;
	else
		cout << abs(n2a - n2b) + abs(n3a - n3b) + abs(n5a - n5b);


}

int main()
{

	#ifndef ONLINE_JUDGE
		freopen("input.txt", "r", stdin);
		freopen("output.txt", "w", stdout);
	#endif

	ios_base::sync_with_stdio(false);
	cin.tie(0);

	int t = 1;
	// cin >> t;
	while (t--)
	{
		solve();
	}

	return 0;
}