#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
struct node {
  int x, y;
  bool operator<(const node &_) const {
    return x < _.x || (x == _.x && y < _.y);
  }
} A[2005];
int h, w, n;
long long dp[2005], jie[200005 << 1], inv[200005 << 1];
long long Pow(long long x) {
  int n = mod - 2;
  long long res = 1;
  while (n) {
    if (n & 1) res = res * x % mod;
    x = x * x % mod;
    n >>= 1;
  }
  return res;
}
void Init() {
  jie[0] = inv[0] = 1;
  for (int i = 1; i < 200005; i++) {
    jie[i] = 1LL * jie[i - 1] * i % mod;
    inv[i] = Pow(jie[i]);
  }
}
long long C(int a, int b) {
  return 1LL * jie[a] * inv[b] % mod * inv[a - b] % mod;
}
int main() {
  Init();
  scanf("%d%d%d", &h, &w, &n);
  for (int i = 1; i <= n; i++) scanf("%d%d", &A[i].x, &A[i].y);
  sort(A + 1, A + n + 1);
  A[n + 1].x = h, A[n + 1].y = w;
  for (int i = 1; i <= n + 1; i++) {
    dp[i] = C(A[i].x + A[i].y - 2, A[i].x - 1);
    for (int j = 1; j < i; j++) {
      if (A[i].y < A[j].y) continue;
      dp[i] = ((dp[i] -
                C(A[i].x - A[j].x + A[i].y - A[j].y, A[i].x - A[j].x) * dp[j]) %
                   mod +
               mod) %
              mod;
    }
  }
  cout << dp[n + 1] << endl;
  return 0;
}
