#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

#define vi vector<int> 
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define vl vector<ll>
#define pii pair<int, int>

void allprime(int n, bool prime[]) 
{  
    for (int p=2; p*p<=n; p++) 
    { 
        if (prime[p] == true) 
        { 
            for (int i=p*p; i<=n; i += p) 
                prime[i] = false; 
        } 
    }
}

void bfs(vi adj[], int src, bool vis[], int level[])
{
	queue<pii> q;
	q.push(mp(src,0));
	vis[src]=true;
	level[src]=0;

	while(!q.empty())
	{
		pii vpair=q.front();
		q.pop();
		int v=vpair.ff;
		int lvl=vpair.ss;

		for(int i=0;i<adj[v].size();i++)
		{
			int next=adj[v][i];
			if(!vis[next])
			{
				q.push(mp(next,lvl+1));
				vis[next]=true;
				level[next]=lvl+1;
			}
		}
	}
}

void dfs(vi adj[], int src, bool vis[])
{
	vis[src]=true;
	for(int i=0;i<adj[src].size();i++)
	{
		int next=adj[src][i];
		if(!vis[next])
		{
			dfs(adj,next,vis);
		}
	}
}




void solve()
{
	// bool vis[6]={false};
	// int level[6];
	// dfs(adj,0,vis);
	// bfs(adj,0,vis,level);
	ll n,k;
	cin>>n>>k;
	if(k<0)
		k*=-1;
	ll ansup, ansdown, ans=0;
	for(int j=2;j<=2*n-k;j++)
	{
		ll up = j+k;
		if(j>n+1)
			ansdown=2*n-j+1;
		else
			ansdown=j-1;
		if(up>n+1)
			ansup=2*n-up+1;
		else
			ansup=up-1;
		// cout<<ansup<<" "<<ansdown<<endl;
		ans+=ansup*ansdown;

	}
	cout<<ans<<endl;
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(NULL); cout.tie(NULL);
	int t=1;
	// cin>>t;
	while(t--)
	{
		solve();
	}
}
/*{{{*/
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<string>
#include<iostream>
#include<sstream>
#include<set>
#include<map>
#include<queue>
#include<bitset>
#include<vector>
#include<limits.h>
#include<assert.h>
#define SZ(X) ((int)(X).size())
#define ALL(X) (X).begin(), (X).end()
#define REP(I, N) for (int I = 0; I < (N); ++I)
#define REPP(I, A, B) for (int I = (A); I < (B); ++I)
#define FOR(I, A, B) for (int I = (A); I <= (B); ++I)
#define FORS(I, S) for (int I = 0; S[I]; ++I)
#define RS(X) scanf("%s", (X))
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#define GET_POS(c,x) (lower_bound(c.begin(),c.end(),x)-c.begin())
#define CASET int ___T; scanf("%d", &___T); for(int cs=1;cs<=___T;cs++)
#define MP make_pair
#define PB emplace_back
#define MS0(X) memset((X), 0, sizeof((X)))
#define MS1(X) memset((X), -1, sizeof((X)))
#define LEN(X) strlen(X)
#define F first
#define S second
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
typedef long double LD;
typedef pair<int,int> PII;
typedef vector<int> VI;
typedef vector<LL> VL;
typedef vector<PII> VPII;
typedef pair<LL,LL> PLL;
typedef vector<PLL> VPLL;
template<class T> void _R(T &x) { cin >> x; }
void _R(int &x) { scanf("%d", &x); }
void _R(int64_t &x) { scanf("%lld", &x); }
void _R(double &x) { scanf("%lf", &x); }
void _R(char &x) { scanf(" %c", &x); }
void _R(char *x) { scanf("%s", x); }
void R() {}
template<class T, class... U> void R(T &head, U &... tail) { _R(head); R(tail...); }
template<class T> void _W(const T &x) { cout << x; }
void _W(const int &x) { printf("%d", x); }
void _W(const int64_t &x) { printf("%lld", x); }
void _W(const double &x) { printf("%.16f", x); }
void _W(const char &x) { putchar(x); }
void _W(const char *x) { printf("%s", x); }
template<class T,class U> void _W(const pair<T,U> &x) {_W(x.F); putchar(' '); _W(x.S);}
template<class T> void _W(const vector<T> &x) { for (auto i = x.begin(); i != x.end(); _W(*i++)) if (i != x.cbegin()) putchar(' '); }
void W() {}
template<class T, class... U> void W(const T &head, const U &... tail) { _W(head); putchar(sizeof...(tail) ? ' ' : '\n'); W(tail...); }
#ifdef HOME
 #define DEBUG(...) {printf("[DEBUG] ");W(__VA_ARGS__);}
#else
 #define DEBUG(...)
#endif
int MOD = 1e9+7;
void ADD(LL& x,LL v){x=(x+v)%MOD;if(x<0)x+=MOD;}
/*}}}*/
const int SIZE = 1<<20;
LL N,K;
void solve() {
    LL an=0;
    FOR(i,2,2*N){
        LL need = i-K;
        if(need<2 || need > 2*N)continue;
        an+=min(i-1LL,2*N+1-i)*min(need-1LL,2*N+1-need);
    }
    W(an);
}
void input() {
    R(N,K);    
}
int main(){
    input();
    solve();
    return 0;
}
