// Marcin Knapik
#include<bits/stdc++.h>
 
#pragma GCC optimize("O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
 
using namespace std;
 
//#include <ext/pb_ds/assoc_container.hpp> // order_of_key
//#include <ext/pb_ds/tree_policy.hpp> // find by order
//using namespace __gnu_pbds; 
//#define ordered_set tree< int , null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>  
 
// const ll MAX_LL = 0xFFFFFFFFFFFFFFFF;
// mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define losuj(a, b) uniform_int_distribution<ull>(a, b)(rng)
#define losuj_real(a, b) uniform_real_distribution<long double>(a, b)(rng)
 
typedef long double             ld;
typedef long long               ll;
typedef unsigned long long      ull;
typedef pair<ll, ll>            pll;
typedef pair<int, int>          ii;
typedef vector<int>             vi;
typedef vector<ii>              vii;
typedef vector<vi>              vvi;
typedef vector<vector<ii>>      vvii;
typedef vector< ll >            vll;
typedef vector< pll >           vpll;
 
#define sz(a)                   (int)(a).size()
#define pb                      push_back
#define all(c)                  (c).begin(), (c).end()
#define rall(c)                 (c).rbegin(), (c).rend()
#define FOR(i, a)               for (int i = 0; i < (a); i++)
#define f                       first
#define s                       second
#define rr "\e[31m "
#define bb "\e[m "
 
template <class T> inline bool setmin(T &a, T b){if (a > b)return a = b, 1;return 0;}
template <class T> inline bool setmax(T &a, T b){if (a < b)return a = b, 1;return 0;}
 
template<class T> inline  T fast(T a,T b,T mod) {ll res = 1; while(b){if(b&1) res = (res*a)%mod;a = (a*a)%mod;b >>= 1;}return res;}
template<class T> inline  T russian(T a, T b, T mod) {ll res = 0; while(b){if(b&1) res = (res + a)%mod; a = (a+a)%mod; b>>=1;}return res;}
template<class T> istream &operator>>(istream &os, vector<T> &container){for (auto &u : container)os >> u;return os;}
template<class T> ostream &operator<<(ostream &os, const vector<T> &container){for (auto &u : container)os << u << " ";return os;}
template<class T> inline  T gcd(T a, T b) { while (b)swap(a %= b, b); return a; }
 
const ll INF = 1e9 + 7;
const ll mod = 998244353;
const ll N = 1e6+7;
const ll T = 1<<20;
const ll BIG_INF = 1e18 + 7;
 
ll n, m, k;
 
ll nr(ii a){
	return 1ll*a.f*N + a.s;
}
 
ll sil[N];
ll odwr[N];
 
map < ll, int > mapa;
map < ll, vector < pair < ll, ll > > > G;
map < ll, ll > parz;
map < ll, ll > nparz;
 
ll dwumian(int a, int b){
	return (sil[a] * odwr[b] % INF) * odwr[a - b] % INF;
}
 
void prep(){
	sil[0] = 1;
	for(int i = 1; i < N; i++)
		sil[i] = sil[i - 1] * i % INF;
	odwr[N - 1] = fast(sil[N - 1], INF - 2, INF);
	for(int i = N - 2; i >= 0; i--)
		odwr[i] = odwr[i + 1] * (i + 1) % INF;
}
 
int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);	
 
	prep();
	
	cin >> n >> m >> k;
 
	vii pkt;
	pkt.pb({1, 1});
 
	FOR(i, k){
		int a, b;
		cin >> a >> b;
 
		pkt.pb({a, b});
	}	
 
	pkt.pb({n, m});
 
	sort(all(pkt));

	for(int i = 0; i < sz(pkt); i++)
		for(int j = i+1; j < sz(pkt); j++){
			int A = pkt[j].s - pkt[i].s;
			int B = pkt[j].f - pkt[i].f;

			if(A >= 0 && B >= 0){
				G[nr(pkt[i])].pb({nr(pkt[j]), dwumian(A + B, A)});
				mapa[nr(pkt[j])]++;
			}
		}
	
	
	queue<ll> kol;
	kol.push(nr({1, 1}));
	parz[nr({1, 1})] = 1;
 
	while(sz(kol)){
		ll x = kol.front();
		kol.pop();
 
		for(auto & u : G[x]){
			mapa[u.f]--;
			if(mapa[u.f] == 0)
				kol.push(u.f);
			
			(parz[u.f] += nparz[x] * u.s) %= INF;
			(nparz[u.f] += parz[x] * u.s) %= INF;
		}
	}
 
	cout << (nparz[nr({n, m})] - parz[nr({n, m})] + INF) % INF << '\n';
}	

Measured memory_bytes: 108032