Task: Program Execution
Input (English): 4751, a, e, 6341, 7023, 7541, a, 4611, a, 9103, K, d, A, t, E, B, g, 1255, 4961, e, o
Output (English): 2, 3, 7, 9, 11, 12, 13, 14, 15, 16, 17, 20, 21