program xxx;
uses crt;
function c(t,k: integer): longint;
  begin
   if (k=0) or (k-t=1) then c:=1
   else
   if k-t>1 then c:=0
   else
   c:=c(t-1, k-1)+c(t-1,k);
  end;
var t,k: integer;
BEGIN
clrscr;
writeln('Ââåäèòå êîëè÷åñòâî 0 è 1');
readln(t,k);
writeln(c(t,k));
readln;
END.