#include <bits/stdc++.h>
using namespace std;
#define _MACRO(_1, _2, _3, NAME, ...) NAME
#define _repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define _rep(i,n) _repl(i,0,n)
#define rep(...) _MACRO(__VA_ARGS__, _repl, _rep)(__VA_ARGS__)
#define pb push_back
#define all(x) begin(x),end(x)
#define uniq(x) sort(all(x)),(x).erase(unique(all(x)),end(x))
#ifdef LOCAL
#define dbg(...) _dbg(#__VA_ARGS__, __VA_ARGS__)
void _dbg(string){cerr<<endl;}
template<class H,class... T> void _dbg(string s,H h,T... t){int l=s.find(',');cerr<<s.substr(0,l)<<" = "<<h<<", ";_dbg(s.substr(l+1),t...);}
template<class T,class U> ostream& operator<<(ostream &o, const pair<T,U> &p){o<<"("<<p.first<<","<<p.second<<")";return o;}
template<class T> ostream& operator<<(ostream &o, const vector<T> &v){o<<"[";for(T t:v){o<<t<<",";}o<<"]";return o;}
#else
#define dbg(...) {}
#endif

template<int mod=1000000007>
class ModInt {
  int x;
public:
  ModInt() : x(0) {}
  ModInt(const ModInt &y): x(y.x) {}
  ModInt(int64_t y){ x = y % mod; if(x < 0) x += mod; }
  ModInt &operator += (const ModInt &p){ x += p.x; if(x >= mod) x -= mod; return *this; }
  ModInt &operator -= (const ModInt &p){ x -= p.x; if(x < 0) x += mod; return *this; }
  ModInt &operator *= (const ModInt &p){ x = (int) (1LL * x * p.x % mod); return *this; }
  ModInt &operator /= (const ModInt &p){ *this *= p.inverse(); return *this; }
  ModInt operator -() const { return ModInt(-x); }
  ModInt operator + (const ModInt &p) const { return ModInt(*this) += p; }
  ModInt operator - (const ModInt &p) const { return ModInt(*this) -= p; }
  ModInt operator * (const ModInt &p) const { return ModInt(*this) *= p; }
  ModInt operator / (const ModInt &p) const { return ModInt(*this) /= p; }
  ModInt operator ^ (const int64_t y) const { return pow(y); }
  bool operator == (const ModInt &p) const { return x == p.x; }
  bool operator != (const ModInt &p) const { return x != p.x; }
  ModInt operator = (const int64_t y) { return *this = ModInt(y); }
  ModInt inverse() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while(b > 0){
      t = a/b; a -= t*b; swap(a, b);
      u -= t*v; swap(u, v);
    }
    return ModInt(u);
  }
  ModInt pow(int64_t y) const {
    if(x==0) return ModInt(0);
    int64_t r = 1, t = x;
    while(y > 0){
      if(y&1) r = r*t%mod;
      t = t*t%mod; y >>= 1;
    }
    return ModInt(r);
  }
  friend ostream &operator << (ostream &os, const ModInt<mod> &p) { return os<<p.x; }
  friend istream &operator >> (istream &is, ModInt<mod> &a) { int64_t x; is>>x; a = ModInt<mod>(x); return is; }
};
using Int = ModInt<>;

const int X = 200005;

Int dp[3005];
Int fact[X+5];
Int finv[X+5];

int main(){
  int h,w,n;
  cin>>h>>w>>n;

  fact[0] = 1;
  rep(i,X) fact[i+1] = fact[i] * (i+1);
  finv[X] = fact[X].inverse();
  for(int i=X-1; i>=0; i--) finv[i] = finv[i+1] * (i+1);

  auto comb = [&](const int x, const int y){
    return fact[x+y] * finv[x] * finv[y];
  };

  vector<pair<int,int>> v(n);
  rep(i,n) cin>>v[i].first>>v[i].second;
  v.pb({h,w});

  sort(all(v));

  rep(i,n+1){
    dp[i] = comb(v[i].first - 1, v[i].second - 1);
    rep(j,i){
      if(v[j].second <= v[i].second){
        dp[i] -= dp[j] * comb(v[i].first - v[j].first, v[i].second - v[j].second);
      }
    }
  }

  cout << dp[n] << endl;

  return 0;
}

// dp[i]
// = はじめてi番目の壁にぶつかるような場合の数
// = comb(r[i],c[i]) - (j<iな各jにおいて、j番目の壁に最初にぶつかり、その後自由な経路でi番目の壁まで到達)
// = comb(r[i],c[i]) - sum_{j < i} (dp[j] * comb(r[i]-r[j], c[i]-c[j]))


Measured memory_bytes: 1920