Chef started watching a movie that runs for a total of X minutes.

Chef has decided to watch the first Y minutes of the movie at twice the usual speed as he was warned by his friends that the movie gets interesting only after the first Y minutes.

How long will Chef spend watching the movie in total?

Note: It is guaranteed that Y is even.

------ Input Format ------

• The first line contains two space separated integers X, Y - as per the problem statement.

------ Output Format ------

• Print in a single line, an integer denoting the total number of minutes that Chef spends in watching the movie.

------ Constraints ------

$1 ≤ X, Y ≤ 1000$
$Y$ is an even integer.

------ subtasks ------

Subtask #1 (100 points): original constraints

----- Sample Input 1 ------
100 20
----- Sample Output 1 ------
90
----- explanation 1 ------
For the first $Y = 20$ minutes, Chef watches at twice the usual speed, so the total amount of time spent to watch this portion of the movie is $\frac{Y}{2} = 10$ minutes.

For the remaining $X - Y = 80$ minutes, Chef watches at the usual speed, so it takes him $80$ minutes to watch the remaining portion of the movie.

In total, Chef spends $10 + 80 = 90$ minutes watching the entire movie.

----- Sample Input 2 ------
50 24
----- Sample Output 2 ------
38
----- explanation 2 ------
For the first $Y = 24$ minutes, Chef watches at twice the usual speed, so the total amount of time spent to watch this portion of the movie is $\frac{Y}{2} = 12$ minutes.

For the remaining $X - Y = 26$ minutes, Chef watches at the usual speed, so it takes him $26$ minutes to watch the remaining portion of the movie.

In total, Chef spends $12 + 26 = 38$ minutes watching the entire movie.

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