#include <cstring>
#include <cassert>
#include <utility>
#include <iostream>
#include <cstdio>
#include <iomanip>
#include <bitset>
#include <chrono>
#include <cstdlib>
#include <functional>
#include <tuple>
#include <climits>
#include <limits>
#include <deque>
#include <list>
#include <array>
#include <stack>
#include <queue>
#include <random>
#include <complex>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <algorithm>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

#define ll              long long
#define pi              pair<int,int>
#define pll             pair<ll,ll>
#define pb              push_back
#define F               first
#define S               second
#define vi              vector<int>
#define vll             vector<ll>
#define endl            '\n'
#define all(v)          (v).begin(),(v).end()
#define FOR(i,a,b)      for(int i=a;i<b;i++)
#define MP(a,b)         make_pair(a,b)
#define debug(x)        cerr<< #x << " : " << x << endl;
#define debugp(p)       cerr<< #p << " : " << "(" << (p).first << "," << (p).second << ")\n";
#define debugv(v)       cerr<< #v << " : " << "["; for(int i = 0; i < (v).size(); i++) cerr << v[i] << " "; cerr<<"]\n";
#define debugs(m)       cerr<< #m << " : [ "; for(auto itr = m.begin(); itr != m.end(); itr++) cerr <<*itr << " "; cerr << "]\n";
#define debugm(m)       cerr<< #m << " : [ "; for(auto itr = m.begin(); itr != m.end(); itr++) cerr <<"(" << itr->first << "," << itr->second << ") "; cerr << "]\n";

/* ordered set: 
tree<T, null_type,less<T>, rb_tree_tag,tree_order_statistics_node_update>
member functions :
1. order_of_key(k) : number of elements strictly lesser than k
2. find_by_order(k) : k-th element in the set
*/

inline ll modexp(ll x, ll ex , ll md) {
    ll ans = 1ll;
    while (ex > 0) {
        if (ex & 1ll) ans = (ans * x) % md;
        ex >>= 1ll;
        x = (x * x) % md;
    }
    return ans;
}

const int inf = 1e9 + 7;
const int maxn = 2e5 + 9;
const ll mod = 1e9 + 7;

ll fact[maxn];
ll minv (ll x , ll md){
  return modexp (x , md - 2 , md);
}

ll ncr (ll n , ll r){
  ll ans = fact[n];
  ll den = fact[r];
  den *= fact[n - r];
  den %= mod;
  ans *= minv (den , mod);
  ans %= mod;
  return ans;
}
void solve(){
  int h , w , n;
  cin >> h >> w >> n;
  for (int i = 0; i < maxn; i++){
    fact[i] = 1ll;
    if (i > 0) fact[i] = 1ll * i * fact[i - 1];
    fact[i] %= mod;
  }
  vector<pair<int , int>> v;
  for (int i = 0; i < n; i++){
    int x , y;
    cin >> x >> y;
    v.emplace_back (x , y);
  }
  v.emplace_back (h , w);
  sort (v.begin() , v.end());
  assert (v.back () == make_pair (h , w));
  int nn = (int) v.size();
  vector<long long> dp (nn);
  for (int i = 0; i < nn ; i++){
    int ir = v[i].first;
    int ic = v[i].second;
    dp[i] = ncr (ir - 1 + ic - 1 , ir - 1);
    for (int j = 0; j < i; j++){
      int jr = v[j].first;
      int jc = v[j].second;
      if (jc <= ic){
        ll thj = dp[j] * ncr (ir - jr + ic - jc , ir - jr);
        thj %= mod; 
        dp[i] -= thj;
        dp[i] %= mod;
        if (dp[i] < 0) dp[i] += mod;
      }
    }
  }
  cout << dp.back() << endl;
}
int main(){
    ios :: sync_with_stdio(false); 
    cin.tie(nullptr); 
    cout.tie(nullptr);
    
    int T = 1;
    // cin >> T;
    for(int tc = 1; tc <= T; tc++){
        // cout << "Case #" << tc << ": ";
        solve();
    }
    #ifdef LOCAL
    cerr << "Time elapsed\t: " << 1000 * ((double)clock()) / (double)CLOCKS_PER_SEC << "ms\n";       
    #endif
}



Measured memory_bytes: 5296