program main
  implicit none
  integer*8::DA
  integer*8,allocatable::a(:)
  integer::i
  read *,DA
  allocate(a(0:DA))
  a = 0
  read *,a(0:DA)

  do i=DA, 3, -1
     a(i-2) = a(i-2) + a(i)
  end do

  if(a(2).ne.0) then
     print '(i0)', 2
     print '(i0,1x,i0,1x,i0)', a(0:2)
  else if(a(1).ne.0) then
     print '(i0)', 1
     print '(i0,1x,i0)', a(0:1)
  else
     print '(i0)', 0
     print '(i0)', a(0)
  end if
end program main