{W I C H T I G     W I C H T I G     W I C H T I G    W I C H T I G}
{VOR STARTEN IM MENš OPTIONS/COMPILER  8087/80287 EINSTELLEN!!!!!!!}
Program Isabel;
{unit nuberk; }
{interface    }

 uses crt;
 type nk=array [2..1000] of integer;
      kn=array [2..1000] of integer;
 var nn:nk;
     kk:kn;
    a,i,n,k:integer;
    answer,answer2:extended;

procedure Fullen;
begin
 if (n=k) or (k=0) then answer:=1
 else
 begin
  if k<(n/2) then begin
   for i:=n-k+1 to n do
    begin
     nn[i]:=i;
     answer:=answer*nn[i];
    end;
   for i:=2 to k do
    begin
     kk[i]:=i;
     answer2:=answer2*kk[i];
    end;
  end
  else
  begin
   for i:=k+1 to n do
    begin
     nn[i]:=i;
     answer:=answer*nn[i];
    end;
   for i:=2 to n-k do
    begin
     kk[i]:=i;
     answer2:=answer2*kk[i];
    end;
  end
 end;
answer:=answer/answer2;
end;

{H a u p t p r o g r a m m}
begin
answer:=1;answer2:=1;clrscr;
readln(n);
readln(k);
if (k=1) then answer:=n else Fullen;
textcolor(9);
writeln((answer));
readln;
end.