You are given a matrix with $n$ rows and $m$ columns. Currently, you are at position $(1, 1)$, and your goal is to move to position $(n, m)$. However, there are $k$ obstacles, meaning you cannot move to the cells occupied by these obstacles. Count the number of ways to move from cell $(1, 1)$ to $(n, m)$.
Every move, you can choose to move from $(i,j)$ to either $(i + 1, j)$ or $(i, j + 1)$.
### Input
- The first line contains three integers $n$, $m$, and $k$.
- The next $k$ lines each contain two integers $x$ and $y$, representing the position of an obstacle at row $x$, column $y$.
### Output
- Output the number of ways to move, modulo $10^9+7$.
### Constraints
- $1 \le n , m \le 10^5$.
- $1 \le k \le 100$.
- $1 \le x \le n$.
- $1 \le y \le m$.
### Example
Input:
```
2 2 1
1 2
```
Output:
```
1
```
