Task: Program Execution
Input (English): P, t, C, r, 7, c, d
Output (English): [['P', 't', 'C', 'r', '7', 'c'], ['P', 't', 'C', 'r', '7', 'd'], ['P', 't', 'C', 'r', 'c', 'd'], ['P', 't', 'C', '7', 'c', 'd'], ['P', 't', 'r', '7', 'c', 'd'], ['P', 'C', 'r', '7', 'c', 'd'], ['t', 'C', 'r', '7', 'c', 'd']]