Consider the database that has the relation schema T (X, Y). An instance of the schema T is as given below:

T1 ← ∏_Y (σ _{X = A3} (T))

T2 ← T ÷ T1

X	Y
A1	B1
A1	B2
A2	B1
A2	B2
A1	B3
A3	B1
A3	B2
A2	B1
A4	B1
A3	B3
A4	B2

Find the number of rows in T2