#include <bits/stdc++.h>
using namespace std;
long long fact[(long long)(1e6 + 10)], mod_inv[(long long)(1e6 + 10)];
long long _pow(long long a, long long n) {
  if (n == 0) return 1;
  if (n % 2 == 1) return (a * _pow(a, n - 1)) % (long long)(1e9 + 7);
  long long x = _pow(a, n / 2) % (long long)(1e9 + 7);
  return (x * x) % (long long)(1e9 + 7);
}
void inv() {
  mod_inv[0] = 1;
  for (int i = 1; i < (long long)(1e6 + 10) - 1; i++) {
    mod_inv[i] = _pow(fact[i], (long long)(1e9 + 7) - 2);
  }
}
void f() {
  fact[0] = 1;
  mod_inv[0] = 1;
  for (int i = 1; i < (long long)(1e6 + 10) - 1; i++) {
    fact[i] = fact[i - 1] * i;
    fact[i] %= (long long)(1e9 + 7);
    mod_inv[i] = _pow(fact[i], (long long)(1e9 + 7) - 2);
  }
}
void init() { f(); }
long long nCr(long long n, long long r) {
  return (((mod_inv[n - r] * mod_inv[r]) % (long long)(1e9 + 7)) * fact[n]) %
         (long long)(1e9 + 7);
}
pair<long long, long long> black[2010];
bool cmp(pair<long long, long long> a, pair<long long, long long> b) {
  return (a.first == b.first) ? a.second < b.second : a.first < b.first;
}
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  init();
  int h, w, n;
  cin >> h >> w >> n;
  for (int i = 0; i < n; i++) {
    cin >> black[i].first >> black[i].second;
    black[i].first--;
    black[i].second--;
  }
  long long dp[n + 1];
  memset(dp, 0, sizeof(dp));
  black[n] = make_pair(h - 1, w - 1);
  sort(black, black + n, cmp);
  for (int i = 0; i < n + 1; i++) {
    dp[i] = nCr(black[i].first + black[i].second, black[i].first);
    for (int j = 0; j < i; j++) {
      if (black[j].second > black[i].second) continue;
      dp[i] -= (dp[j] * nCr(black[i].first - black[j].first + black[i].second -
                                black[j].second,
                            black[i].second - black[j].second)) %
               (long long)(1e9 + 7);
      dp[i] += (long long)(1e9 + 7);
      dp[i] %= (long long)(1e9 + 7);
    }
  }
  cout << dp[n] << endl;
  return 0;
}
