program ch1902a
implicit none
real :: d,e,f
  d = 1000.0
  e =   20.0
  call divide(d,e,f)
  print *,f
end program ch1902a

subroutine divide(a,b,c)
implicit none
integer , intent(in) :: a
integer , intent(in) :: b
integer , intent(out):: c
  c=a/b
end subroutine divide