Task: Program Execution
Input (English): Y, S, 1837, Y, G, 8487, H, 4963, F, 581, 2413, B, e, Z, 3927, p, s, 4819, 6979, 5113, M
Output (English): 1, 2, 4, 5, 7, 9, 12, 13, 14, 16, 17, 21