Task: Program Execution
Input (English): 3, 6, ['1977', '2839', 'S', '6117', 'J', 'x', '7941', 'C', '4891', 't', '2889', 'I', 'A', '3885', '6923', 'r', 'b', '3991']
Output (English): S, 4891, 6923