Source

This problem is adapted from Long Long OJ. All rights reserved.

Problem Description

Little A has two sticks of length $a$ and little B has two sticks of length $b$.

Determine how many distinct lengths can be formed by combining their sticks (not all sticks need to be used).

Input Format

One line containing two non-negative integers $a$ and $b$, separated by a space.

Output Format

The number of distinct lengths that can be formed using the four sticks (not all need to be used).

Samples

2 2

5

2 3

9

Sample 2 Explanation

Possible lengths formed: $0, 2, 3, 4, 5, 6, 7, 8, 10$.

Data Range

$0 \le a, b \le 10^{18}$.