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

int main()
{
	int a,b;
	cin >> a >> b;
	if(b==0)
	{
		cout<<1<<endl;
		return 0;
	}
	ll n = 0;
	for(int i = 0;i<3;i++)
	{
		n = n*a+b;
		if(n==0)
		{
			cout<<i+1<<endl;
			return 0;
		}
	}
	cout<<-1<<endl;
}