Task: Program Execution
Input (English): 6123 6387 4631 4923 a 6833 f 3649 u W g i h 9003 Y i 409 H 6295 p O 2101 923 P 275 Z 3237 6179 o
Output (English): 1, 2, 3, 4, 6, 8, 14, 17, 19, 22, 23, 25, 27, 28