A variable x is said to be live at a statement S_i in a program if the following three conditions hold simultaneously:
I. There exists a statement S_j that uses x
II. There is a path from S_i to S_j in the flow graph corresponding to the program
III. The path has no intervening assignment to x including at S_i and S_j

The variables which are live at the statement in basic block 2 and at the statement in basic block 3 of the above control flow graph are