css        parameter ( nx =128, ny =128, npop = 9)
css        parameter ( nx =256, ny = 128, npop = 9)
        parameter (nx =64, ny = 32, npop = 9)
	character*5 fileout
	logical iforce,iobst

	common /constants/ cs2,cs22,cssq,rho,omega,fpois,den,visc,
     .                     rt0,rt1,rt2
        common /phys/   u0,uf,fom
	common /arrays/ u(0:nx+1,0:ny+1),v(0:nx+1,0:ny+1),
     .                  feq(0:npop-1,0:nx+1,0:ny+1),
     .                  f(0:npop-1,0:nx+1,0:ny+1)
	
	common /count/ istep,nout,ndiag,nsteps,nobst	
	common /ile/ fileout
	common /logic/ iforce,iobst