Task: Program Execution
Input (English): W 3959 Z 7777 8245 X x 7577 B a l 3139 5721 4289 L 1371 9541 N 6839 9829 s 5041 3271 639 6475 W W A F U a 6717
Output (English): 1, 3, 6, 7, 9, 10, 11, 15, 18, 21, 26, 27, 28, 29, 30, 31