3. In triangle $\mathrm{ABC}$, angle $\mathrm{C}$ is twice as small as angle $\mathrm{B}$. $\mathrm{BB}_{1}$ is the bisector of angle $\mathrm{B}, \mathrm{D}$ is the point of intersection of the circumcircle of triangle $\mathrm{ABB}_{1}$ and side $\mathrm{AB} . \mathrm{BD}=14$, $\mathrm{CD}=18$. Find the length of $\mathrm{AC}$.

If there are multiple correct answers, list them in any order separated by a semicolon.
Answer: 30.

## Examples of answer notation:

45

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