XF XB IB
= 2 lower beds & 2 upper beds / = 2 lower beds & 1 upper bed / = double bed / = 2 lower beds
= 2 lower beds & 2 upper beds / 
= 2 lower beds & 1 upper bed / 
= double bed / 
= 2 lower beds = 2 lower beds & 2 upper beds / = 2 lower beds & 1 upper bed / = double bed / = 2 lower beds