Let $R(A,B[S{]}_{2}C)$ and $S(D_{,}E,F)$ be relations with attributes $A,B,C$ and $D,E,F,$ respectively, where A and $B|S|$ are primary keys in $R$ with $B$ being a foreign key pointing on $S$ and $D$ is a primary key in $S.$

We assume that all attributes are in $\{1,$dots,$9\}$ and that $C$ NOT NULL and $E$ UNIQUE hold. Moreover, assume that only the following tuples are already stored in $R$ and $S,$ respectively:

$R(1,2,3)(2,3,4)$

$S(2,1,1)(3,2,4)(4,5,6)$

What is the Cardinality of $R?$