A centipede has 40 left feet and 40 right feet. It keeps *a* left slippers
and *b* right slippers under its bed. Every morning the centipede puts on
the slippers. It pokes its first left foot under the bed and puts on a
random slipper, doing it in one second. If the slipper is left, the
centipede passes to shoeing the second left foot. Otherwise, it takes off
the slipper and puts it on any unshod right foot, spending one more
second, so that it takes two seconds altogether to put on such a slipper.
If there are no unshod right feet, the centipede throws the slipper to a
corner of the room, also in one second, so that two seconds are spent
altogether for this slipper. The process is continued until all the left
feet are in left slippers. Then the centipede starts shoeing its right
feet until all of them are shod.

Today the centipede has got out of bed on the wrong side, so it is
preparing for the worst. How many seconds will it need for shoeing?

### Input

The only line contains the integers *a* and *b* (40 ≤ *a*, *b* ≤ 100).

### Output

Output the number of seconds the centipede will need for shoeing in the
worst case.

### Sample

**Problem Author: **Mikhail Rubinchik

**Problem Source: **Ural Regional School Programming Contest 2011