Task: Program Execution
Input (English): 2921, f, 2709, R, 1771, 6849, 3255, j, 4343, 2671, 2985, g, U, l, 7447, U, L, 7781, 3909
Output (English): 1, 3, 5, 6, 7, 9, 10, 11, 15, 18, 19