Border Cells

Time limit1sMemory limit1024 MB

Summary

Given the dimensions m and n of a rectangle on a grid, count how many cells lie on its border.

Problem

Anya has a grid sheet of paper, and on it she drew a rectangle of size $m \times n$ .

Then she colored the cells of the rectangle that lie on its border.

How many cells did Anya color?

The first line contains an integer $m$ ( $1 \le m \le 10^8$ ).

The second line contains an integer $n$ ( $1 \le n \le 10^8$ ).

Print one integer, the number of cells Anya colored.