var f, g:text;
    rez, n, k:longint;
    fol, vg, v, sol:array[1..20] of longint;

procedure verificare;
var s, j, i, nr:longint;
  begin
    v:=vg;
    nr:=0;
    for i:=1 to n do
      begin
        v[sol[i]]:=1;
        s:=0;
        for j:=1 to i do
          s:=s+v[j];
        if s=i then
          begin
            nr:=nr+1;
            if nr>k then
              break;
          end;
      end;
    if nr=k then
      rez:=rez+1;
  end;

procedure gen(poz:longint);
var i:longint;
  begin
    if poz=n+1 then
      verificare
     else
       begin
         for i:=1 to n do
           if fol[i]=0 then
             begin
               fol[i]:=1;
               sol[poz]:=i;
               gen(poz+1);
               fol[i]:=0;
             end;
       end;

  end;

  begin
    assign(f,'permutari2.in'); reset(f);
    assign(g,'permutari2.out'); rewrite(g);
    read(f,n,k);

    gen(1);
    writeln(g,rez);
    close(f);
    close(g);
  end.