Task: Program Execution
Input (English): 5, 7, ['x', 'B', '6829', 'c', 'K', '3021', 'U', '9989', 's', 'c', '345', '4423', 'j', 'S', 'E', 'r', 't', 'F', '1739', 'y']
Output (English): K3021U