Problem Statement

There is a train going from Station $A$ to Station $B$ that costs $X$ yen (the currency of Japan).

Also, there is a bus going from Station $B$ to Station $C$ that costs $Y$ yen.

Joisino got a special ticket. With this ticket, she can take the bus for half the fare if she travels from Station $A$ to Station $B$ by train and then travels from Station $B$ to Station $C$ by bus.

How much does it cost to travel from Station $A$ to Station $C$ if she uses this ticket?

Constraints

• $1 \leq X,Y \leq 100$
• $Y$ is an even number.
• All values in input are integers.

Input

Input is given from Standard Input in the following format:

X Y

Output

If it costs $x$ yen to travel from Station $A$ to Station $C$, print $x$.