KöMaL 2023 C1787

In acute triangle $ABC$ we draw a parallel line through orthocenter $M$ with side $AB$, which intersects sides $AC$ and $BC$ in points $D$ and $E$, respectively. Let $CC_1$ be the diameter of the circumcircle of triangle $ABC$. Find the perimeter of triangle $DEC_1$, given that $AB=14$.