#include <bits/stdc++.h>
using namespace std;
using ll = long long;
// --------------------------------------------------------
template<class T> bool chmax(T& a, const T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T& a, const T b) { if (b < a) { a = b; return 1; } return 0; }
#define FOR(i,l,r) for (ll i = (l); i < (r); ++i)
#define RFOR(i,l,r) for (ll i = (r)-1; (l) <= i; --i)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define SORT(c) sort(ALL(c))
#define RSORT(c) sort(RALL(c))
#define MIN(c) *min_element(ALL(c))
#define MAX(c) *max_element(ALL(c))
#define SUMLL(c) accumulate(ALL(c), 0LL)
#define SZ(c) ((ll)(c).size())
#define BIT(b,i) ((b>>i) & 1)
#define PCNT(b) __builtin_popcountll(b)
#define CIN(c) cin >> (c)
#define COUT(c) cout << (c) << '\n'
#define debug(x) cerr << "l." << __LINE__ << " : " << #x << " = " << (x) << '\n'
ll llceil(ll a, ll b) { return (a + b - 1) / b; }
string toupper(const string& S) { string T(S); REP(i,SZ(T)) T[i] = toupper(T[i]); return T; }
string tolower(const string& S) { string T(S); REP(i,SZ(T)) T[i] = tolower(T[i]); return T; }
using P = pair<ll,ll>;
using VP = vector<P>;
using VVP = vector<VP>;
using VS = vector<string>;
using VVS = vector<VS>;
using VLL = vector<ll>;
using VVLL = vector<VLL>;
using VVVLL = vector<VVLL>;
using VB = vector<bool>;
using VVB = vector<VB>;
using VVVB = vector<VVB>;
using VD = vector<double>;
using VVD = vector<VD>;
using VVVD = vector<VVD>;
static const double EPS = 1e-10;
static const double PI  = acos(-1.0);
static const ll MOD = 1000000007;
// static const ll MOD = 998244353;
static const ll INF = (1LL << 62) - 1;  // 4611686018427387904 - 1
// --------------------------------------------------------
// #include <atcoder/all>
// using namespace atcoder;


int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);

    ll B, C; cin >> B >> C;

    if (C == 0) { COUT(1); return 0; }

    ll ans = 1;  // B or -B
    if (B == 0) {
        // 0 --> INF
        ans += (C-2) / 2;
        // 0 --> -INF
        ans += C / 2;
    } else if (B > 0) {
        ans++;  // -B
        // B --> 0
        ans += min(C/2, B);
        // B --> INF
        ans += (C-2) / 2;
        // B ---> -1
        ans += min((C-1)/2, B-1);
        // B --> -INF
        ans += (C-1) / 2;
    } else {
        ans++;  // B
        // -B --> 0
        ans += min((C-1)/2, -B);
        // -B --> INF
        ans += (C-1) / 2;
        // -B ---> -1
        ans += min((C-1)/2, -B-1);
        // -B --> -INF
        ans += C / 2;
    }
    COUT(ans);

    return 0;
}

//#pragma GCC optimize("O3")
#include<bits/stdc++.h>
#define eps 1e-9
#define MOD1 998244353
#define MOD2 1000000007
#define INV_2 499122177
#define INF 1000000000
#define PI 3.14159265358979323846

using namespace std;

int main()
{
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	long long x, k, i;
	cin >> x >> k;
	i=x;
	if(x < 0)
		x-=(2*x);
	unsigned long long ans;
	if(x==0)
	{
		ans=1;
		ans+=(k/2)+(k/2)-1+(k%2);
	}
	else
	{
		ans=2;
		if(i > 0)
		{
			if(k > 1)
				ans+=(k-1)/2+(k-1)/2-1+((k-1)%2);
			if(k/2 >= x)
				ans+=2*x-1;
			else
				ans+=(k/2)+(k/2)-1+(k%2);
		}
		else
		{
			ans+=(k/2)+(k/2)-1+(k%2);
			if(((k-1)/2) >= x)
				ans+=2*x-1;
			else if(k > 1)
				ans+=(k-1)/2+(k-1)/2-1+((k-1)%2);
		}
	}
	cout << ans << '\n';
}
//size	