I have a very basic question. $\mathsf{P}$ is the class of decision problems solvable in polynomial time by a Turing machine. $\oplus \mathsf{P}$ is the class of decision problems solvable by an NP machine such that
- If the answer is 'yes,' then the number of accepting paths is odd.
- If the answer is 'no,' then the number of accepting paths is even.
How do you show that $L \in \mathsf P \implies L \in \oplus \mathsf P$? i.e., that $\mathsf{P} \subseteq \oplus \mathsf{P}$.