Consider the following tables T1 and T2

In table T1, P is the primary key and Q is the foreign key referencing R in table T2 with on delete cascade and on-update cascade. In table T2, R is the primary key and S is the foreign key referencing P in table T1 on-delete set NULL and on-update cascade. In order to delete record 3,8 from table T1, the number of additional records that need to be deleted from table T1 is _____.