  The progenitor mass of type IIP supernova can be determined from either
hydrodynamic modeling of the event or pre-explosion observations. To compare
these approaches, we determine parameters of the sub-luminous supernova 2005cs
and estimate its progenitor mass. We compute the hydrodynamic models of the
supernova to describe its light curves and expansion velocity data. We estimate
a presupernova mass of 17.3 Msun, an explosion energy of 4.1x10^{50} erg, a
presupernova radius of 600 Rsun, and a radioactive Ni-56 mass of 0.0082 Msun.
The derived progenitor mass of SN 2005cs is 18.2 Msun, which is in-between
those of low-luminosity and normal type IIP supernovae. The obtained progenitor
mass of SN 2005cs is higher than derived from pre-explosion images. The masses
of four type IIP supernovae estimated by means of hydrodynamic modeling are
systematically higher than the average progenitor mass for the 9-25 Msun mass
range. This result, if confirmed for a larger sample, would imply that a
serious revision of the present-day view on the progenitors of type IIP
supernovae is required.
