#include <iostream>
#include <iomanip>
#include <string>
#include <vector>
#include <queue>
#include <algorithm>
#include <utility>
#include <cmath>
#include <map>
#include <set>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cassert>
#include <cctype>
#include <complex>
using namespace std;

#define INF_LL (ll)1e18
#define INF (int)1e9
#define REP(i, n) for(int i = 0;i < (n);i++)
#define FOR(i, a, b) for(int i = (a);i < (b);i++)
#define all(x) x.begin(),x.end()
using ll = long long;
using PII = pair<int, int>;

const double eps = 1e-10;

template<typename A, typename B>inline void chmin(A &a, B b){if(a > b) a = b;}
template<typename A, typename B>inline void chmax(A &a, B b){if(a < b) a = b;}

map<PII, int> cnt;

int main(void){
	int x, y;
	cin >> x >> y;
	cnt[PII(x, y)] = -1;
	queue<PII> q;
	q.push({x, y});
	while(q.size()){
		x = q.front().first; y = q.front().second; q.pop();
		if(x == y){
			cout << (cnt[PII(x, y)] == -1 ? 0 : cnt[PII(x, y)]) << endl;
			return 0;
		}
		int now = cnt[PII(x, y)];
		if(now == -1) now = 0;
		if(cnt[PII(y, x)] == 0){
			cnt[PII(y, x)] = now+1;
			q.push({y, x});
		}
		if(abs(x+y) < 10000 && abs(x-y) < 10000 && cnt[PII(x+y, x-y)] == 0){
			cnt[PII(x+y, x-y)] = now+1;
			q.push({x+y, x-y});
		}
	}
	cout << -1 << endl;
}