Let $ABCDE$ be an inscribed pentagon such that $\angle B +\angle E = \angle C +\angle D$.Prove that $\angle CAD < \pi/3 < \angle A$. (Proposed by B.Frenkin)
Problem
Source: Sharygin Geometry Olympiad Correspondence round 2016 P-8 Grade 8-9
Tags: inequalities, geometry