Task: Program Execution
Input (English): 3705, a, 7567, 5903, 5589, 2623, 7495, b, 897, 4125, 6769, f, 8519, x, 5629, Z, H, x, c, Y, y, 8409, 1567
Output (English): 1, 3, 4, 5, 6, 7, 9, 10, 11, 13, 15, 22, 23