1, 11, 12, 21, 100, 101, 102, 111, 112, 121, 122, 131, 132, 141, 142, 151, 152, 161, 162, 171, 172, 181, 182, 191, 192, 201, 1000, 1001, 1002, 1011, 1012, 1021, 1022, 1031, 1032, 1041, 1042, 1051, 1052, 1061, 1062, 1071, 1072, 1081, 1082, 1091, 1092, 1101