  We study the two-dimensional (2D) dilatonic model describing a massless
scalar field minimally coupled to the spherically reduced Einstein-Hilbert
gravity. The general solution of this model is given in the case when a Killing
vector is present. When interpreted in four dimensions, the solution describes
either a static or a homogeneous collision of incoming and outgoing null dust
streams with spherical symmetry. The homogeneous Universe is closed.
