  We propose an exactly solvable model to describe the properties of atomic
thickness hybrid ferromagnet-superconductor-ferromagnet (F/S/F) structures. We
show that the superconducting critical temperature is always higher for
antiparallel orientation of the ferromagnetic moments. However at low
temperature the superconducting gap occurs to be larger for parallel
orientation of the ferromagnetic moments. This leads to a peculiar temperature
dependence of the proximity effect in (F/S/F) structures.
