Task: Program Execution
Input (English): o, f, 7869, 3643, 3415, 4637, 9137, 7397, c, s, 2595, 4345, k, 7299, e, 1259, 4615, o, 3123, 5149, k, 3701, b, 415
Output (English): b, c, e, f, k, o, s