#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
template <class T>
void out(T x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  if (x > 9) out(x / 10);
  putchar(x % 10 + '0');
}
long long dp[2005];
struct node {
  int x, y;
} a[2005];
bool cmp(node a, node b) {
  if (a.x == b.x) return a.y < b.y;
  return a.x < b.x;
}
long long O[201005], I[201005];
long long C(int a, int b) { return O[a] * I[b] % mod * I[a - b] % mod; }
int main() {
  O[0] = 1;
  for (int i = 1; i < 200105; i++) O[i] = O[i - 1] * i % mod;
  I[0] = I[1] = 1;
  for (int i = 2; i < 200105; i++) I[i] = mod / i * (mod - I[mod % i]) % mod;
  for (int i = 1; i < 200105; i++) I[i] = I[i] * I[i - 1] % mod;
  int h, w, n;
  scanf("%d%d%d", &h, &w, &n);
  for (int i = 0; i < n; i++) scanf("%d%d", &a[i].x, &a[i].y);
  sort(a, a + n, cmp);
  long long ans = C(h + w - 2, h - 1);
  for (int i = 0; i < n; i++) {
    dp[i] = C(a[i].x + a[i].y - 2, a[i].y - 1);
    for (int j = 0; j < i; j++)
      if (a[j].x <= a[i].x && a[j].y <= a[i].y) {
        dp[i] = (dp[i] -
                 dp[j] * C(a[i].x - a[j].x + a[i].y - a[j].y, a[i].x - a[j].x) +
                 mod) %
                mod;
      }
    ans = (ans - dp[i] * C(h - a[i].x + w - a[i].y, h - a[i].x) + mod) % mod;
  }
  out((ans + mod) % mod);
  return 0;
}
