#include <iostream>
using namespace std;

typedef long long ll;

int main() {
    ll b, c;
    cin >> b >> c;
    if (b == 0) {
        cout << c << endl;
    }
    else if (b > 0) {
        if (c < 3) cout << min(2 * b, c) + 1 << endl;
        else cout << min(2 * b, c) + c - 1 << endl;
    }
    else {
        if (c < 3) cout << c + 1 << endl;
        else cout << c + min(2 * (-b), c - 1) << endl;
    }
}
/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author Kein Yukiyoshi
 */

// clang-format off
#include <bits/stdc++.h>
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx")
#define int long long
using namespace std;
#define stoi stoll
#define fi first
#define se second
#define rep(i, n) for(int i=0, i##_len=(n); i<i##_len; i++)
#define rep2(i, a, b) for (int i = (int)(a), i##_len=(b); i < i##_len; i++)
#define rep3(i, a, b) for (int i = (int)(a), i##_len=(b); i >= i##_len; i--)
#define FOR(i, a) for (auto &i: a)
#define ALL(obj) begin(obj), end(obj)
#define _max(x) *max_element(ALL(x))
#define _min(x) *min_element(ALL(x))
#define _sum(x) accumulate(ALL(x), 0LL)

const int MOD   = 1000000007;
// const int MOD    = 998244353;
const int INF    = (int)(1e13 + 7);
const double EPS = 1e-8;
const double PI  = 3.14159265358979;
template <class T> using V = vector<T>;
template <class T> using VV = vector<vector<T>>;
template <class T> using VVV = vector<vector<vector<T>>>;
template <class T, class S>  using P = pair<T, S>;
template<class T> bool chmax(T &a, const T &b) {if (a < b) {a = b;return true;}return false;}
template<class T> bool chmin(T &a, const T &b) {if (b < a) {a = b;return true;}return false;}
int _ceil(int a, int b) { return (a >= 0 ? (a + (b - 1)) / b : (a - (b - 1)) / b); }
int _mod(int a) {return a >= 0 ? a % MOD : a - (MOD * _ceil(a, MOD));}
int _pow(int a, int b) {int res = 1;for (a %= MOD; b; a = a * a % MOD, b >>= 1)if (b & 1) res = res * a % MOD;return res;}
struct mint {long long x;mint(long long x = 0) : x((x % MOD + MOD) % MOD) {}mint operator-() const { return mint(-x); }mint &operator+=(const mint a) {if ((x += a.x) >= MOD) x -= MOD;return *this;}mint &operator-=(const mint a) {if ((x += MOD - a.x) >= MOD) x -= MOD;return *this;}mint &operator*=(const mint a) { (x *= a.x) %= MOD;return *this; }mint operator+(const mint a) const { return mint(*this) += a; }mint operator-(const mint a) const { return mint(*this) -= a; } mint operator*(const mint a) const { return mint(*this) *= a; }mint pow(long long t) const {if (!t) return 1;mint a = pow(t >> 1);a *= a;if (t & 1) a *= *this;return a;}mint inv() const { return pow(MOD - 2); }mint &operator/=(const mint a) { return *this *= a.inv(); }mint operator/(const mint a) const { return mint(*this) /= a; }};istream &operator>>(istream &is, mint &a) { return is >> a.x; }ostream &operator<<(ostream &os, const mint &a) { return os << a.x; }
// clang-format on

class BB {
public:
  static void solve(istream &cin, ostream &cout) {
    cin.tie(nullptr);
    cout.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(15);
    int B, C;
    cin >> B >> C;
    int ans = 0;
    if (B > 0) {
      ans++;
      if (C / 2 >= B) {
        ans += B;
      } else {
        ans += C / 2;
      }
      if ((C - 1) / 2 >= B - 1) {
        ans += B;
      } else {
        ans += (C - 1) / 2 + 1;
      }
      C--;
      ans += C / 2;
      ans += (C - 1) / 2;
    } else if (B == 0) {
      ans++;
      ans += C / 2 + (C - 1) / 2;
    } else {
      ans++;
      ans += C / 2;
      ans += (C - 1) / 2;
      ans++;
      C--;
      B *= -1;
      if (C / 2 >= B) {
        ans += B;
      } else {
        ans += C / 2;
      }
      if ((C - 1) / 2 >= B - 1) {
        ans += B - 1;
      } else {
        ans += (C - 1) / 2;
      }
    }
    cout << ans << endl;
  }
};


signed main() {
  BB solver;
  std::istream& in(std::cin);
  std::ostream& out(std::cout);
  solver.solve(in, out);
  return 0;
}
