# include <fstream>
# define DIM 5000010
using namespace std;
ifstream fin("pascal.in");
ofstream fout("pascal.out");
int v[DIM],n,i,c,d,nr;
int main () {
    fin>>n>>d;
    c=d;
    if(d==4)
        c=2;
    if(d==6)
        c=3;
    for(i=1;i<=n;i++){
        v[i]=v[i-1];
        if(i%c==0)
            v[i]+=i/c;
    }
    for(i=0;i<=n;i++){
        if(d==4){
            if(v[n]>v[i]+v[n-i]+1)
                nr++;
            continue;
        }
        if(v[n]>v[i]+v[n-i])
            nr++;
    }
    fout<<nr<<"\n";
    return 0;
}