Task: Program Execution
Input (English): 6523, 121, f, 1187, 7869, 6579, 4621, 1359, 99, v, F, Z, 3389, R, 1793, v, 9831, 7625, 1709, d
Output (English): f, v, F, Z, R, v, d, 6523, 121, 1187, 7869, 6579, 4621, 1359, 99, 3389, 1793, 9831, 7625, 1709