So the blue one begins at the five end and goes all the way to the three N, while the pink begins at the three N and goes all the way to the five end. And this is what we mean by the antiparallel directionality, where one of our single stranded DNA runs from the five to three, while the other one runs from the three to five. Now, one other thing that we have to notice is that the sugar as well as the phosphate within our double stranded DNA points outside of that DNA while inside that double stranded DNA double helix structure, we have our nitrogenous basis. So that is shown by the following diagram. So this line basically represents the sugar and the phosphate, while these squares represent our nitrogenous bases. And our nitrogenous bases are basically protected and are found inside our double stranded DNA molecule.