Let $a=3^{1/223}+1$ and for all $n \ge 3$ let \[f(n)= \dbinom{n}{0} a^{n-1} - \dbinom{n}{1} a^{n-2} + \dbinom{n}{2} a^{n-3}- ... +(-1)^{n-1} \dbinom{n}{n-1} a^0.\] Find  $f(2007)+f(2008).$

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