#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
#define vv(a,b,c,d) vector<vector<a> >(b,vector<a>(c,d))
#define vvv(a,b,c,d,e) vector<vector<vector<a> > >(b,vv(a,c,d,e))
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

const int MA = 3010, OFF = 1000;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(20);

    using T = tuple<int, int, int>;
    queue<T> Q;
    auto vis = vv(int, MA, MA, 0);

    int x, y;
    cin >> x >> y;
    Q.push(T(0,x+OFF, y+OFF));
    vis[x + OFF][y + OFF] = 1;

    while (!Q.empty()) {
        int d, z, w;
        tie(d, z, w) = Q.front();
        Q.pop();
        if (z == w) {
            cout << d << endl;
            RT 0;
        }

        if (!vis[w][z]) {
            vis[w][z] = 1;
            Q.push(MT(d + 1, w, z));
        }
        x = z - OFF;
        y = w - OFF;
        int nx = x + y;
        int ny = x - y;
        z = nx + OFF;
        w = ny + OFF;
        if (z >= 0 && w >= 0 && z < MA&&w < MA && !vis[z][w]) {
            vis[z][w] = 1;
            Q.push(MT(d + 1, z, w));
        }
    }
    cout << -1 << endl;
}