Task: Program Execution
Input (English): 6601, 3375, 643, 9421, 5209, s, X, 543, 1073, l, 7445, 7571, 2071, u, v, 5207, 8605, Z, G, 4443, d, 4427
Output (English): 6, 7, 10, 14, 15, 18, 19, 21