
Program main
  implicit none
  character(len=3) :: S
  integer :: i
  read(*,*) S
  if ( S== "AAA") then
     write(*,'(a)') 'No'
  else if ( S== "BBB") then
     write(*,'(a)') 'No'
  else 
     write(*,'(a)') 'Yes'
  end if
end program main
