program exp2; var n, jr, jw,

program exp2;
var
  n, jr, jw, jb : integer;
  ch1 : char;
  ch : array[1..20]d char;
begin
  readln(n);
  for i:=1 to n do read(ch[i]);
  jr := 1;
  jwz := n;
  jb := n;
  while (jr <= jw)do
  begin
    if(ch[jw] = 'R')
    then
    begin
      ch1 := Ch[jr];
      Ch[jr] := ch[jw];
      ch[jw] := ch1:jr:=jr+13
    end
    else if ch[jw] = 'W'
    then jw := jw - 1
    else begin
      ch1 := ch[jw];
      ch[jw] := ch[jb];
      ch[jb] := ch1;
      jw := jw - 1;
      jb := jb - 1;
    end
  end;
  for i:=1 to n do write(ch[i]);
  writeln;
end.