HMMT 2023 G8

Triangle $A B C$ with $\angle B A C>90^{\circ}$ has $A B=5$ and $A C=7$. Points $D$ and $E$ lie on segment $B C$ such that $B D=D E=E C$. If $\angle B A C+\angle D A E=180^{\circ}$, compute $B C$.