  The paper studies a discrete dynamical system, which belongs to the class of
contour systems developed by A.P Buslaev. The system contains two closed
contours. There are n cells and a group of particles at each contour. This
group is called a cluster. The particles of a cluster are in adjacent cells and
move simultaneously. At each discrete moment any particle moves onto a cell in
the direction of movement. There are two common points of contours called
nodes. Delays of clusters occur at the nodes. These delays are due to that two
particles cannot cross the same node simultaneously. Earlier this system were
studied under the assumptions that the number of particles does not depend on
the cluster. This paper studies a system with different lengths of clusters.
Analytical results are obtained for limit cycles of the system and the spectrum
of average cluster velocities.
