/* -*- coding: utf-8 -*-
 *
 * 643.cc: No.643 Two Operations No.2 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_X = 200;
const int MAX_Y = 200;
const int INF = 1 << 30;

/* typedef */

typedef vector<int> vi;
typedef queue<int> qi;
typedef pair<int,int> pii;

/* global variables */

int dp[MAX_X * 2 + 1][MAX_Y * 2 + 1];

/* subroutines */

/* main */

int main() {
  int x, y;
  scanf("%d%d", &x, &y);

  memset(dp, -1, sizeof(dp));
  dp[x + MAX_X][y + MAX_Y] = 0;
  int mind = -1;

  queue<pii> q;
  q.push(pii(x, y));

  while (! q.empty()) {
    pii u = q.front(); q.pop();
    int &ux = u.first, &uy = u.second;
    int &ud = dp[ux + MAX_X][uy + MAX_Y], vd = ud + 1;

    if (ux == uy) {
      mind = ud;
      break;
    }

    // op 1
    if (dp[uy + MAX_X][ux + MAX_Y] < 0) {
      dp[uy + MAX_X][ux + MAX_Y] = vd;
      q.push(pii(uy, ux));
    }

    // op 2
    int vx = ux + uy, vy = ux - uy;
    if (vx >= -MAX_X && vx <= MAX_X && vy >= -MAX_Y && vy <= MAX_Y &&
	dp[vx + MAX_X][vy + MAX_Y] < 0) {
      dp[vx + MAX_X][vy + MAX_Y] = vd;
      q.push(pii(vx, vy));
    }
  }

  printf("%d\n", mind);
  return 0;
}