1111\u0031\u0031 (C99)\U000031\U000031 (C99)\x31\x31 (encoding-dependent)\061\061 (encoding-dependent)\u{31}\u{31} (C++23)\x{31}\x{31} (C++23, encoding-dependent)\o{061}\o{061} (C++23, encoding-dependent)\U00000031\U00000031\u0031\u0031\x31\x31 (encoding-dependent)\061\061 (encoding-dependent)\u0031\u0031\u{31}\u{31}\u0031\u0031\x31\x31\31\31\000031\000031=31=31%31%31