recursive function qsort(x) result(y)
  integer,intent(in)     ::x(:)
  integer,allocatable::y(:)
  integer::pivot,total
  total = size(x)
  if (total <=1) then
     y = x
  else
     pivot = x(total/2)
     y = [qsort(pack(x, x .lt. pivot)), &
          pack(x, x .eq. pivot),        &
          qsort(pack(x, x .gt. pivot))]
  endif
end function qsort

program main
  interface
     recursive function qsort(x) result(y)
       integer,intent(in)     ::x(:)
       integer,allocatable::y(:)
     end function qsort
  end interface
  integer::total
  integer,dimension(1000)::x,y
  data x/1000*1001/
  read *,total
  read *,(x(i),i=1,total)

  y = qsort(x)

  if (mod(total,2).eq.1) then
     print '(f0.1)',y(total/2+1)*1.0
  else
     print '(f0.1)',(y(total/2)+y(total/2+1)) /2.0
  endif
end program main