ff\u0066 (C99)\U000066 (C99)\x66 (encoding-dependent)\146 (encoding-dependent)\u{66} (C++23)\x{66} (C++23, encoding-dependent)\o{146} (C++23, encoding-dependent)\U00000066\u0066\x66 (encoding-dependent)\146 (encoding-dependent)\u0066\u{66}\u0066\x66\66\000066=66%66