Task: Program Execution
Input (English): W, 3099, 5181, z, 275, i, 7849, I, 5111, y, o, K, S, u, i, R, 6481, 1909, S, x, G
Output (English): 1, 4, 6, 8, 10, 11, 12, 13, 14, 15, 16, 19, 20, 21