In triangle $ABC$, points $D$ and $E$ lie on the interior of segments $AB$ and $AC$, respectively, such that $AD = 1$, $DB = 2$, $BC = 4$, $CE = 2$, and $EA = 3$. Let $DE$ intersect $BC$ at $F$. Determine the length of $CF$.

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