program main
  implicit none
  integer N
  integer(8) A(10**5), koyakusu_TOP, dai, sho, koyakusu, yakurow(10**5)
  integer i, j, t
  
  read(*, *) N
  read(*, *) (A(i), i = 1,N)
  koyakusu_TOP = 1
  yakurow = 0
  do t = 1,N
    do i = 1,N-1
      do j = i+1,N
        dai = max(A(i),A(j))
        sho = min(A(i),A(j))
        koyakusu = yaku(dai,sho)
        if (koyakusu > koyakusu_TOP .and. i/=t .and. j/=t) then
          koyakusu_TOP = koyakusu
        end if
      end do
    end do
    yakurow(t) = koyakusu_TOP
  end do
  if (N == 2) then
    write(* ,'(i0)') max(A(1),A(2))
  else
    write(* ,'(i0)') maxval(yakurow)
  end if


  
  stop
contains

  
  integer(8) function yaku(dai, sho)
    implicit none
    integer(8) dai, sho, ans, dai2
    do while (mod(dai,sho) /= 0)
      dai2 = mod(dai, sho)
      dai = sho
      sho = dai2
    end do
    yaku = sho
    return
  end function yaku
      
      
end program main
