#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
using namespace std;

int main()
{
    int x, y;
    cin >> x >> y;

    vector<pair<int, int> > v(1, make_pair(x, y));
    for(int i=0; i<10; ++i){
        vector<pair<int, int> > w;
        for(const auto& p : v){
            int a, b;
            tie(a, b) = p;
            if(a == b){
                cout << i << endl;
                return 0;
            }
            w.push_back(make_pair(a+b, a-b));
            w.push_back(make_pair(b, a));
        }
        v.swap(w);
    }

    cout << -1 << endl;
    return 0;
}