3939\u0033\u0039 (C99)\U000033\U000039 (C99)\x33\x39 (encoding-dependent)\063\071 (encoding-dependent)\u{33}\u{39} (C++23)\x{33}\x{39} (C++23, encoding-dependent)\o{063}\o{071} (C++23, encoding-dependent)\U00000033\U00000039\u0033\u0039\x33\x39 (encoding-dependent)\063\071 (encoding-dependent)\u0033\u0039\u{33}\u{39}\u0033\u0039\x33\x39\33\39\000033\000039=33=39%33%39