def solve(self):
if not isinstance(self.cube, Cube):<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>for i in range(<NUM_LIT:4>):<EOL><INDENT>rec_id = self.recognise()<EOL>if rec_id in algo_dict:<EOL><INDENT>self.cube(algo_dict[rec_id])<EOL>return Formula((Step("<STR_LIT:y>") * i) or []) + algo_dict[rec_id]<EOL><DEDENT>self.cube(Step("<STR_LIT:y>"))<EOL><DEDENT>raise ValueError("<STR_LIT>")<EOL>
Solve PLL of Cube.