The analysis of the efficiency of accretion in the X-ray binary system A 0535 + 26/HDE 245770 and of the specific angular momentum of the matter accreted during its X-ray outbursts leads to the conclusion that there are two disks present in the system. An excretion disk around the Be star HDE 245770 and an accretion disk (possibly temporary) around the neutron star A 0535 + 26. The two failures of the pulsar to produce the expected X-ray outbursts in 1985-86 indicate that probably there exists a state in which the pulsar remains 'fast' (i.e., rotates faster than it would correspond to its instantaneous equilibrium period) during the whole orbital cycle, including the periastron passages.