Task: Program Execution
Input (English): X, S, Z, o, 8577, 903, n, u, F, Y, B, 7215, 4953, 269, 1867, 3787, N, 6521, k, e, G
Output (English): 1, 2, 3, 4, 7, 8, 9, 10, 11, 17, 19, 20, 21