Task: Program Execution
Input (English): 5171, M, I, 4915, 2753, 4415, 3615, 8679, F, 2553, 2163, 9461, 4993, 1203, 7829, a, c, f, u, Z
Output (English): 2, 3, 9, 16, 17, 18, 19, 20