Task: Program Execution
Input (English): P i d f 775 5639 q U o 2025 4781 1931 5179 X d i f M z E 7683 6563 e 5139 p 7545 f O
Output (English): 1, 2, 3, 4, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 23, 25, 27, 28