#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <string>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <stdio.h>
using namespace std;
#define int long long
int MOD = 1000000007;
signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int X, Y;
	cin >> X >> Y;

	int res = 0;
	queue<pair<pair<int, int>, int> > qu;
	qu.push(make_pair(make_pair(X,Y), 0));
	pair<pair<int,int>, int > p;
	res = -1;
	while (qu.size() > 0) {

		p = qu.front(); qu.pop();
		if (p.first.first == p.first.second) {
			res = p.second;
			break;
		}
		if (p.second > 5)break;
		
		qu.push(make_pair(make_pair(p.first.first + p.first.second, p.first.first - p.first.second), p.second + 1));
		qu.push(make_pair(make_pair(p.first.second, p.first.first), p.second + 1));
		
	}
	cout << res << endl;
}