#include <bits/stdc++.h>
  
using namespace std;
  
#if 1
    #define pv(x) cout<<#x<<" = "<<(x)<<"; ";cout.flush()
    #define pn cout<<endl
#else
    #define pv(x)
    #define pn
#endif
  
// #if 1
#ifdef INFOARENA
    ifstream in("pascal.in");
    ofstream out("pascal.out");
#else
    #define in cin
    #define out cout
#endif
  
using ll = long long;
using ull = unsigned long long;
using uint = unsigned int;
using ld = long double;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
using pld = pair<ld, ld>;
using pdd = pair<double, double>;
#define pb push_back
const long double PI = 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862;
const long double EPS = 1e-8;
const int inf_int = 1e9 + 5;
const ll inf_ll = 1e18 + 5;
const int NMax = 5e6 + 5;
const int mod = 666013;
const int dx[] = {-1,0,0,+1}, dy[] = {0,-1,+1,0};

int occ[NMax];

// intoarce la ce putere se afla numarul prim x in descompunerea lui (fact!);
int getOcc(int fact, int x) {
    if (occ[fact] != 0) {
        return occ[fact];
    }

    int pw = x;
    while (pw <= fact) {
        occ[fact] += fact / pw;
        pw *= x;
    }

    return occ[fact];
}

int main() {
    // cin.sync_with_stdio(false);
    // cin.tie(0);cout.tie(0);

    int N,D;
    in >> N >> D;

    int ans = 0;
    if (D == 4) {
        for (int k = 1; k < N; ++k) {
            int numOcc;
            numOcc = getOcc(N, 2);
            numOcc -= getOcc(k, 2);
            numOcc -= getOcc(N - k, 2);

            if (numOcc >= 2) {
                ans += 1;
            }
        }
    }
    else if (D == 6) {
        for (int k = 1; k < N; ++k) {
            int numOcc2, numOcc3;
            numOcc2 = getOcc(N, 2);
            numOcc2 -= getOcc(k, 2);
            numOcc2 -= getOcc(N - k, 2);

            numOcc3 = getOcc(N, 3);
            numOcc3 -= getOcc(k, 3);
            numOcc3 -= getOcc(N - k, 3);

            if (numOcc2 >= 1 && numOcc3 >= 1) {
                ans += 1;
            }
        }
    }
    else {
        for (int k = 1; k < N; ++k) {
            int numOcc;
            numOcc = getOcc(N, D);
            numOcc -= getOcc(k, D);
            numOcc -= getOcc(N - k, D);

            if (numOcc >= 1) {
                ans += 1;
            }
        }
    }

    out << ans << '\n';
    
    return 0;
}