  We report a direct observation of the crossover of the superconductor-
ferromagnet-superconductor (SFS) junctions to the \pi-state which manifests
itself in the half-period shift of the external magnetic field dependence of
the transport critical current in the triangular SFS arrays. It is associated
with the appearance of spontaneous supercurrents in the array at zero external
field, with the ground state degenerated with respect to the two possible
current flow directions. In conventional Josephson arrays this state can be
observed only by imposing frustrating external field equal to a half-integer
number of magnetic quanta per cell.
