Problems

# Queen Move

# Queen Move

The queen stands on the chessboard of size **m** × **n**. How many squares does the queen attack?

#### Input

Four positive integers: the size of the chessboard **m** and **n** and the queen's coordinates **x** and **y** (**1** ≤ **x** ≤ **m** ≤ `10`

, ^{9}**1** ≤ **y** ≤ **n**≤ `10`

).^{9}

#### Output

Print the number of squares the queen attacks.

Input example #1

8 8 4 5

Output example #1

27

Input example #2

1000000000 3 999999999 2

Output example #2

1000000005