Define $a_k = 2^{2^{k-2013}} + k$ for all integers $k$. Simplify the expression:

$$(a_0 + a_1)(a_1 - a_0)(a_2 - a_1)\cdots(a_{2013} - a_{2012}).$$

Let's think step by step and output the final answer within \boxed{}.
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