Task: Program Execution
Input (English): d, 4181, i, t, y, Y, 5179, a, 3445, 3581, A, 7653, 6811, 7111, t, O, 8975, D, C, 5067, K
Output (English): 1, 3, 4, 5, 6, 8, 11, 15, 16, 18, 19, 21