Sean $a_0, a_1, \dots, a_n$ números del intervalo $(0, \pi/2)$ tales que
\[\tan\left(a_0 - \frac{\pi}{4}\right) + \tan\left(a_1 - \frac{\pi}{4}\right) + \dots + \tan\left(a_n - \frac{\pi}{4}\right) \geq n - 1.\]
Demostrar que
\[\tan a_0 \cdot \tan a_1 \cdot \dots \cdot \tan a_n \geq n^{n+1}.\]