//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define FIO ios_base::sync_with_stdio(false); cin.tie(0);
#define trav(x,a) for (auto& x: a)
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define mem(a,v) memset((a), (v), sizeof (a))
#define endl "\n"
#define case(t) cout << "Case #" << (t) << ": "
#define reada(a, n) for (int _i = 0; _i < (n); _i++) read(a[_i])
#define pii pair<int, int>
#define pll pair<long long, long long>
#define vii vector<pii>
#define vll vector<pll>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define mp make_pair
#define st first
#define nd second
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef cc_hash_table<int,int,hash<int>> ht;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
const double pi = acos(-1);
const int mod = 1e9 + 7;
const int inf = 1e9 + 7;
const int N = 1e6 + 5;
const double eps = 1e-9;

template<class T> void read(T& x) { cin >> x; }
template<class X, class Y> void read(pair<X,Y>& a) { read(a.first), read(a.second); }
template<class T, size_t U> void read(array<T,U>& x) { for (int i = 0; i < U; i++) read(x[i]); }
template<class T> void read(vector<T>& x) { trav(y, x) read(y); }
template<class T, class... O> void read(T& x, O&... y) { read(x), read(y...); }

string to_string(const char& x) { return string(1,x); }
string to_string(const char*& x) { return (string)x; }
string to_string(const string& x) { return x; }
template<class T, class U> string to_string(const pair<T,U>& x) { return to_string(x.first) + " " + to_string(x.second); }
template<class T, size_t U> string to_string(const array<T,U>& x) { string ret = ""; for (int i = 0; i < U; i++) ret += (!i ? "" : " ") + to_string(x[i]); return ret; }
template<class T> string to_string(const vector<T>& x) { string ret = ""; bool f = 0; trav(y, x) ret += (!f ? "" : " ") + to_string(y), f = 1; return ret; }
template<class T> string to_string(const set<T>& x) { string ret = ""; bool f = 0; trav(y, x) ret += (!f ? "" : " ") + to_string(y), f = 1; return ret; }
void print() { cout << endl; }
template<class T> void pr(const T& x) { cout << to_string(x); }
template<class T, class... O> void print(const T& x, const O&... y) { pr(x); if (sizeof...(y)) pr(" "); print(y...); }

int sm[N];

int main() {
  FIO
  int n, k; read(n, k);
  ll ans = 0;
  for (int i = 2; i <= 2 * n; i++) {
    sm[i] = min(2*n-(i-1), i-1);
  }
  for (int i = 2; i <= 2 * n; i++) {
    if (2 <= i + k && i + k <= 2 * n)
      ans += sm[i] * 1ll * sm[i + k];
  }
  print(ans);
  return 0;
}

// ConsoleApplication1.cpp : Defines the entry point for the console application.
//

#include <stack>
#include <iostream>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <algorithm>
#include <cmath>
#include <queue>
#include <climits>

#define MAXCHAR 255
#define ll long long

using namespace std;
const ll dividend = 1000000007;
const ll limit = pow(10, 18);
const ll bigNum = pow(10, 9);
const int intMax = 2147483647;

ll funcComb(int n, int k)
{
	ll output = 1;
	int sum = n + k;
	vector<int> dividends;
	for (int i = 0; i < k; i++)
	{
		dividends.push_back(k - i);
	}
	for (int i = 0; i < k; i++)
	{
		output *= sum - i;
		for (auto it = dividends.begin(); it != dividends.end(); it++)
		{
			if (*it == 0)
				continue;
			if (output % *it == 0)
			{
				output /= *it;
				*it = 0;
			}
		}
		if (output > dividend)
		{
			output %= dividend;
		}
	}

	return output;
}

ll funcPow(int n, int r)
{
	ll ret = 1;
	for (int i = 1; i <= r; i++)
	{
		ret *= n;
		if (ret > dividend)
			ret %= dividend;
	}
	return ret;
}



int main()
{
	double a, b, out = 0;
	cin >> a >> b;
	out = a * b / 100;
	cout << out << endl;
	return 0;
}