Task: Program Execution
Input (English): 7435, 4469, q, 6689, i, s, i, g, 5221, l, 6507, 6329, h, 5371, l, 1849, O, 9563, R, q, i, 3171, I, 1625
Output (English): 3, 5, 6, 7, 8, 10, 13, 15, 17, 19, 20, 21, 23