Task: Program Execution
Input (English): o, 4881, 4069, 7203, 5607, 8603, Y, O, K, 7711, 9869, 2197, 3697, 7139, f, 7267, 2783, N, 6607, 8695, e, 4037
Output (English): 1, 7, 8, 9, 15, 18, 21