So we break this bond here, we produce fragment number one. So let's label this fragment as fragment number one. Then we cleave this bond here, we produce this fragment number two. And we also produce, once we cleave this section here we produce this fragment number four. And notice that because the protolytochemical leaves our disulfide bonds intact these red bonds aren't broken. And so this entire fragment number three actually consists of this green section that came from the green polypeptide and the blue section that came from that blue polypeptide.