Task: Program Execution
Input (English): 7617, 2287, F, L, 9567, 8477, 8971, 5509, 3653, 4417, 1447, 1799, x, J, u, N, D, 1401, 4805, 6139, V, U
Output (English): 1, 2, 5, 6, 7, 8, 9, 10, 11, 12, 18, 19, 20