var buf, s, result:string;
    i: integer;
begin
readln(s);
i :=0;
buf :=''; result:='';
while (i < length(s)) do
 begin
  i := i+1;
  buf:= buf + s[i];
  if (s[i] = ' ') then 
    begin
	  if (length(buf) mod 2 = 0) then  result := result + buf;
	  buf := '';
    end;
 end;
writeln(result);
readln();
end.