program yukicoder_2614
  use, intrinsic :: iso_fortran_env
  implicit none
  integer(int32) :: t
  integer(int32) :: i
  read(input_unit, *) t
  do i = 1, t
     call solve()
  end do
contains
  impure subroutine solve()
    integer(int32) :: n
    character, allocatable :: ans(:)
    integer(int32) :: i
    read(input_unit, *) n
    allocate(ans(3 * n))
    ans(1:6) = ["A", "B", "A", "C", "B", "C"]
    do i = 3, n
       ans(3 * (i - 1) + 1) = "A"
       ans(3 * (i - 1) + 2) = "B"
       ans(3 * (i - 1) + 3) = "C"
    end do
    write(output_unit, '(*(a1))') ans(:)
  end subroutine solve
end program yukicoder_2614