Task: Program Execution
Input (English): 18, 21, ['3067', '5393', 'e', '2071', '3485', 'U', 'v', '935', 'w', 'Z', '8981', '8389', '4769', 'q', 'a', 'r', 'j', 'r', 'C', '7143', 'G']
Output (English): G3417Cr