program yukicoder_746
  use, intrinsic :: iso_fortran_env
  implicit none
  integer(int32), parameter :: maxi = 1000
  integer(int32) :: n, cnts(-maxi:maxi), c
  integer(int32), allocatable :: arr(:)
  integer(int32) :: i, j
  read(input_unit, *) n
  allocate(arr(n))
  read(input_unit, *) arr(:)
  cnts(:) = 0
  do i = 1, n
     cnts(arr(i)) = cnts(arr(i)) + 1
  end do
  c = 0
  do i = -maxi, maxi
     do j = 1, cnts(i)
        c = c + 1
        arr(c) = i
     end do
  end do
  associate(half_1 => (n + 1) / 2, half_2 => (n + 2) / 2)
    write(output_unit, '(g0)') real(arr(half_1) + arr(half_2), real64) / 2
  end associate
end program yukicoder_746