var
                 s : ansistring;
                 i, n : longint;
                begin
                    for i := 1 to 35000 do
                        s := s + 'ab';
                    for i := 1 to 35000 do
                        s := s + 'ba';
                    for i := 1 to 30000 do
                        s := s + 'cd';

                    n := length(s);
                    for i := n - 1 downto 1 do if (s[i] = s[i + 1]) then delete(s, i, 2);
                    writeln(s);
                end.