Task: Program Execution
Input (English): 1579, a, 5481, b, 1855, c, 7939, 5167, u, 1751, G, r, 7729, 8979, 9765, 3927, 9509, 2207, 321, 9357, g
Output (English): 1, 3, 5, 7, 8, 10, 13, 14, 15, 16, 17, 18, 19, 20