  We describe all possible topological structures of Morse-Smale flows without
closed trajectories on a three-dimensional sphere, which have two sources, two
sinks, one saddle of Morse index 1, one saddle of Morse index 2, and no more
than 10 saddle connections. To classify such flows, a generalized Heegaard
diagram or Pr-diagram is used, which in this case consists of a sphere and two
closed curves, the intersection points of which correspond to saddle
connections. We have found all possible, up to homeomorphism, ways to embed two
circles in a 2-sphere with no more than 10 points of transversal intersection
and construct its planar visualisations.
