Task: Program Execution
Input (English): 3841, 6285, A, 6447, 2121, 3317, 6845, b, 8557, U, c, 6809, i, 4467, 9651, 4701, s, 9951, 1437, v, 2749, G
Output (English): 1, 2, 4, 5, 6, 7, 9, 12, 14, 15, 16, 18, 19, 21