Task: Program Execution
Input (English): a, f, g, 4231, 4915, W, Y, k, e, 8675, 5099, 1963, 9931, 4055, 7503, j, 4715, 6053, 2279
Output (English): 4, 5, 10, 11, 12, 13, 14, 15, 17, 18, 19