Task: Program Execution
Input (English): o, 8459, D, 9153, v, 629, 1971, 2047, 4651, m, c, 5675, 1541, x, 4363, i, 9187, Z, 203, S, 4309, X, u
Output (English): 2, 4, 6, 7, 8, 9, 12, 13, 15, 17, 19, 21