#include <bits/stdc++.h>
#define fo(a,b,c) for (a=b; a<=c; a++)
#define fd(a,b,c) for (a=b; a>=c; a--)
#define ll long long
//#define file
using namespace std;

int i,j,k,l;
ll n,K,ans,s;

ll js(int t)
{
	if (t<2 || t>n*2) return 0;
	if (t<=n+1) return t-1;
	return n*2+1-t;
}

int main()
{
	#ifdef file
	freopen("b.in","r",stdin);
	#endif
	
	scanf("%d%d",&n,&K);
	fo(i,2,n+n)
	{
		s=i-K;
		ans+=js(i)*js(s);
	}
	printf("%lld\n",ans);
	
	fclose(stdin);
	fclose(stdout);
	return 0;
}
//Code by Ritik Agarwal
#include<bits/stdc++.h>
using namespace std;
#define sz(x) (int)(x).size() 
#define int long long int
#define loop(i,a,b) for(int i=a;i<b;i++)
#define scan(arr,n) for (int i = 0; i < n; ++i) cin >> arr[i]
#define vi vector<int>
#define si set<int>
#define pii pair <int, int>
#define sii set<pii>
#define vii vector<pii>
#define mii map <int, int>
#define pb push_back
#define ff first
#define ss second
#define all(aa) aa.begin(), aa.end()
#define rall(a) a.rbegin() , a.rend()
#define read(a,b) int a,b;  cin>>a>>b
#define readt(a,b,c) int a,b,c; cin>>a>>b>>c
#define readf(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d;
#define print(v) for(auto x:v) cout<<x<<" ";cout<<endl
#define printPair(res) for(pair<int,int>& p:res) cout<<p.first<<" "<<p.second<<endl;
#define faster ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
//*****  Constants  *****
const int mod = 1000000007; /* 1e9 + 7*/
const int MAXN = 1000005; /*1e6 +5 */
const int mod1= 998244353;
const int NAX=2E5+5;
int vis[MAXN]={0};
int fac[300001];
void fact(int m){fac[0]=1;for(int i=1;i<=300000;i++) fac[i]=(fac[i-1]%m * i%m)%m;}
/* Iterative Function to calculate (x^y)%p in O(log y)*/
long long power( long long x,  int y, int p){   long long res = 1;  
x = x % p; while (y > 0) { if (y & 1)  res = (res * x) % p;  y = y >> 1; x = (x * x) % p;} return res;}
// Returns n^(-1) mod p 
long long modInverse( long long n, int p) {  return power(n, p - 2, p); }
long long nCr( long long n,int r, int p) { if (r == 0) return 1; if(n<r) return 0;
return (fac[n] * modInverse(fac[r], p) % p * modInverse(fac[n - r], p) % p) % p; } 

int binarySearch(vi arr, int l, int r, int x) { 
if (r >= l) { int mid = l + (r - l) / 2; if (arr[mid] == x) return mid; 
if (arr[mid] > x)  return binarySearch(arr, l, mid - 1, x); 
return binarySearch(arr, mid + 1, r, x); } return -1; } 

void solve(int test)
{
read(n,k);
int ans=0;
// loop(a,1,n+1)
// {
//   loop(b,1,n+1)
//   {
//     loop(c,1,n+1)
//     {
//       loop(d,1,n+1)
//       {
//         if(a+b== k+c+d)
//         {
//           cout<<a<<" "<<b<<" "<<c<<" "<<d<<endl;
//           ans++;
//         }
//       }
//     }
//   }
// }
// cout<<ans<<endl;

 ans=0;
 int maxm=1+n;
 int perm[2*n +1]={0};
 perm[2]=1;
 perm[3]=2;
 int tt=0;
 for(int i=4;i<=n+n;i++)
 {
  int me=i-1;
  if(me>n)
    me=n;
int val=((me - (i+1)/2) +1 )*2;
if(i%2==0)
  val--;
  perm[i]=val;
 }
 //cout<<
 k=abs(k);
if(k>=0)
{
      for(int i=2 ; i<=n+n-k ; i++)
      {
        int left=i;
        int right=i+k;
       // cout<<left<<" "<<right<<endl;
        int r1=perm[left] , r2=perm[right];
        ans+=(r1*r2);

      }

}
cout<<ans<<endl;


}

int32_t main()
{
      #ifndef ONLINE_JUDGE
          freopen("input.txt", "r", stdin);
          freopen("output.txt", "w", stdout);
      #endif
      faster;
      //fact(mod);
      int t=1;
     // cin>>t;
      for(int test=1;test<=t;test++)
      {
          solve(test);
      }
}