#include <bits/stdc++.h>
 
using namespace std;
using ll = long long;
// #define int ll
using PII = pair<ll, ll>;
 
#define FOR(i, a, n) for (ll i = (ll)a; i < (ll)n; ++i)
#define REP(i, n) FOR(i, 0, n)
#define ALL(x) x.begin(), x.end()
 
template<typename T> T &chmin(T &a, const T &b) { return a = min(a, b); }
template<typename T> T &chmax(T &a, const T &b) { return a = max(a, b); }
template<typename T> bool IN(T a, T b, T x) { return a<=x&&x<b; }
template<typename T> T ceil(T a, T b) { return a/b + !!(a%b); }
 
template<typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts) { 
  return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}
template<typename T,typename V> typename enable_if<is_class<T>::value==0>::type
fill_v(T &t, const V &v) { t=v; }
template<typename T,typename V> typename enable_if<is_class<T>::value!=0>::type
fill_v(T &t, const V &v ) { for(auto &e:t) fill_v(e,v); }
 
template<class S,class T>
ostream &operator <<(ostream& out,const pair<S,T>& a){
  out<<'('<<a.first<<','<<a.second<<')'; return out;
}
template<typename T>
istream& operator >> (istream& is, vector<T>& vec){
  for(T& x: vec) {is >> x;} return is;
}
template<class T>
ostream &operator <<(ostream& out,const vector<T>& a){
  out<<'['; for(T i: a) {out<<i<<',';} out<<']'; return out;
}
 
int dx[] = {0, 1, 0, -1}, dy[] = {1, 0, -1, 0}; // DRUL
const int INF = 1<<30;
const ll LLINF = 1LL<<60;
const int MOD = 1000000007;

template<bool type=true>
ll combi(ll N_, ll K_, ll mo=MOD) {
  const int NUM_=5e5;
  static ll fact[NUM_+1]={},factr[NUM_+1]={},inv[NUM_+1]={};
  auto binpow = [&](ll x, ll e) -> ll {
    ll a = 1, p = x;
    while(e > 0) {
      if(e%2 == 0) {p = (p*p) % mo; e /= 2;}
      else {a = (a*p) % mo; e--;}
    }
    return a;
  };
  if (fact[0]==0) {
    if(type) {
      fact[0] = factr[0] = inv[0] = 1;
      FOR(i, 1, NUM_+1) fact[i] = fact[i-1] * i % MOD;
      factr[NUM_] = binpow(fact[NUM_], mo-2);
      for(int i=NUM_-1; i>=0; --i) factr[i] = factr[i+1] * (i+1) % MOD;
    } else {
      FOR(i, 1, NUM_+1) fact[i] = fact[i-1] * i % MOD;
      REP(i, NUM_+1) inv[i] = binpow(i, MOD-2);
    }
  }
  if(K_<0 || K_>N_) return 1;
  // 前計算 O(max(N,K)) クエリ O(1)
  if(type) return factr[K_]*fact[N_]%MOD*factr[N_-K_]%MOD;
  // Nが大きいけどKが小さい場合に使う 前計算 O(Klog(mod)) クエリ O(K)
  ll ret = 1;
  for(;K_>0;N_--,K_--) (ret *= N_%MOD) %= MOD, (ret *= inv[K_]) %= MOD;
  return ret;
}

ll dp[2010];
signed main(void)
{
  cin.tie(0);
  ios::sync_with_stdio(false);

  ll h, w, n;
  cin >> h >> w >> n;
  n++;
  vector<ll> y(n), x(n);
  REP(i, n-1) cin >> y[i] >> x[i], y[i]--, x[i]--;
  y[n-1] = h-1, x[n-1] = w-1;

  vector<ll> idx(n);
  iota(ALL(idx), 0);
  sort(ALL(idx), [&](ll l, ll r){
    if(y[l] == y[r]) return x[l] < x[r];
    return y[l] < y[r];
  });

  REP(i, n) {
    dp[i] = combi(x[idx[i]] + y[idx[i]], x[idx[i]]);
    REP(j, i) {
      if(x[idx[j]] <= x[idx[i]] && y[idx[j]] <= y[idx[i]]) {
        ll diffx = x[idx[i]] - x[idx[j]];
        ll diffy = y[idx[i]] - y[idx[j]];
        dp[i] -= dp[j] * combi(diffx + diffy, diffx) % MOD;
        dp[i] += MOD;
        dp[i] %= MOD;
      }
    }
  }
  
  cout << dp[n-1] << endl;

  return 0;
}


Measured memory_bytes: 10112