Constant angle surfaces in product spaces

We classify all the surfaces in M2(c1)×M2(c2) for which the tangent space TpM2 makes constant angles with Tp(M2(c1)×{p2}) (or equivalently with Tp({p1}×M2(c2)) for every point p=(p1,p2) of M2. Here M2(c1) and M2(c2) are 2-dimensional space forms, not both flat. As a corollary we give a classification of all the totally geodesic surfaces in M2(c1)×M2(c2).