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Contest: Task: Related: TaskB

Score : $200$ points

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