I have a difficult high-school competition-level math problem in Lean, and I have several proposed answer.
Your task is to mimic the "majority vote" in Self consistency prompt, and output the most common proposed answer you have found. 
Some answers could look very close, and you can treat them as same answers. You must not attempt to solve the problem and propose your own answer. The output answer must be the most common one from the ones I gave to you.
You must not output things like Answer <index>: <answer>. Only output your final answer like <answer>.
Your output answer should be enclosed with delimiter <<< >>> so i can parse it. You must not write anything else.

