Problem Statement

Takahashi has $A$ untasty cookies containing antidotes, $B$ tasty cookies containing antidotes and $C$ tasty cookies containing poison.

Eating a cookie containing poison results in a stomachache, and eating a cookie containing poison while having a stomachache results in a death. As he wants to live, he cannot eat one in such a situation. Eating a cookie containing antidotes while having a stomachache cures it, and there is no other way to cure stomachaches.

Find the maximum number of tasty cookies that Takahashi can eat.

Constraints

• $0 \\leq A,B,C \\leq 10^9$
• $A,B$ and $C$ are integers.

Input

Input is given from Standard Input in the following format:

$A$ $B$ $C$

Output

Print the maximum number of tasty cookies that Takahashi can eat.

Sample Input 1

3 1 4

Sample Output 1

5

We can eat all tasty cookies, in the following order:

• A tasty cookie containing poison
• An untasty cookie containing antidotes
• A tasty cookie containing poison
• A tasty cookie containing antidotes
• A tasty cookie containing poison
• An untasty cookie containing antidotes
• A tasty cookie containing poison

Sample Input 2

5 2 9

Sample Output 2

10

Sample Input 3

8 8 1

Sample Output 3

9