32916번 - Another Brick in the Wall 다국어

문제

Alice likes building toy walls. She has a lot of 1ドル \times 2$ bricks and a limited supply of 1ドル \times 3$ bricks. Both types of bricks have a height of 1 and can not be rotated.

Alice is going to build a one unit thick wall of length $l$ and height $h$ out of these bricks. A wall is solid if there are no seams directly above another seam.

Help Alice determine the minimum number of 1ドル \times 3$ bricks required to build a solid wall of length $l$ and height $h$.

입력

The only line contains two integers $l$ and $h,ドル denoting the length and the height of the wall (5ドル \le l \le 1000$; 2ドル \le h \le 1000$).

출력

Print the minimum number of 1ドル \times 3$ bricks required to build a solid $l \times h$ wall.

It can be shown that it is always possible to build a solid wall of length $l$ and height $h$.

제한

힌트