Find the total electric flux out of the cylinder out of the ends of the cylinder used as the Gaussian surface in this problem?

Find the total electric flux out of the cylinder out of the ends of the cylinder used as the Gaussian surface in this problem? Electric field is directed along the z axis by symmetry, it is parallel to the curved side walls of the cylinder, so there is no flux through these walls. Express your answer in terms of the area needed constants. Find the charge within the Gaussian surface inside the Gaussian surface?