Maze Connectivity Sum

In a mysterious fantasy continent, there exist $n$ ancient and magical mazes numbered from $1$ to $n$. Some pairs of mazes have bidirectional connections, while others have one-way paths. A player wants to challenge different mazes by starting from maze $m$. Your task is to help him determine the total count by calculating (1) the number of mazes that can directly reach maze $m$, and (2) the number of mazes that maze $m$ can directly reach; then output the sum of these two counts.

Note that for any maze $i$ ($1 \leq i \leq n$), it is always considered to directly reach itself.

inputFormat

The input begins with a line containing two integers $n$ and $m$, where $n$ is the total number of mazes and $m$ is the starting maze. The second line contains an integer $k$, representing the number of direct connections (excluding the implicit self-connection). Each of the following $k$ lines contains two integers $a$ and $b$, indicating there is a direct connection from maze $a$ to maze $b$.

outputFormat

Output a single integer: the sum of the number of mazes that can directly reach maze $m$ and the number of mazes that maze $m$ can directly reach (each maze always directly reaches itself).

sample

4 2
4
1 2
2 3
3 2
2 4

6