   10 program main
         integer   :: a,b
         logical   :: c,d
         real      :: e,f

*        This is only valid code for f77, not f90 (or later)
         real*8    :: g,h

         character ::i,j

*        This is only valid code for f77, not f90 (or later)
         complex*8 :: k,l

         complex   :: m,n
         double precision :: o
   20 end program main
