Consider an Entity-Relationship(ER) model in which entity sets E₁ and E₂ are connected by an m : n relationship R₁₂. E₁ and E₃ are connected by a 1 : n (1 on the side of E₁ and n on the side of E₃) relationship R₁₃. E₁ has two single-valued attributes a₁₁ and a₁₂ of which a₁₁ is the key attribute. E₂ has two single-valued attributes a₂₁ and a₂₂ of which is the key attribute. E₃ has two singlevalued attributes a₃₁ and a₃₂ of which a₃₁ is the key attribute. The relationships do not have any attributes. If a relational model is the derived from the above ER model, then the minimum number of relations that would be generated if all the relations are in 3NF is _______.