#include <bits/stdc++.h>

#if MYDEBUG
#include "lib/cp_debug.hpp"
#else
#define DBG(...) ;
#endif
#if __cplusplus <= 201402L
template <typename T>
T gcd(T a, T b) { return ((a % b == 0) ? b : gcd(b, a % b)); }
template <typename T>
T lcm(T a, T b) { return a / gcd(a, b) * b; }
#endif
using LL = long long;
constexpr LL LINF = 334ll << 53;
constexpr int INF = 15 << 26;
constexpr LL MOD = 1E9 + 7;

namespace Problem {
using namespace std;
template <long long Mod = MOD>
class Modint {
 public:
  long long v;

  Modint(const Modint &x) { v = x.v; }
  explicit Modint(int x) {
    if (x < 0 or Mod <= x) x %= Mod;
    if (x < 0) x += Mod;
    v = x;
  }
  explicit Modint(long long x) {
    if (x < 0 or Mod <= x) x %= Mod;
    if (x < 0) x += Mod;
    v = x;
  }
  explicit Modint(unsigned x) {
    if (Mod <= x) x %= Mod;
    v = x;
  }
  explicit Modint(unsigned long long x) {
    if (Mod <= x) x %= Mod;
    v = x;
  }
  template <typename T>
  explicit Modint(T x) {
    if (x < 0 or Mod <= x) x %= Mod;
    v = x;
  }
  Modint() : v(0) {}
  long long get() const { return v; }
  Modint mpow(Modint &n) const { return mpow(n.v); }
  Modint mpow(long long n) const {
    long long i = 1, p = v;
    Modint ret(1);
    while (i <= n) {
      if (i & n) ret *= p;
      i = (i << 1);
      p = (p * p) % Mod;
    }
    return ret;
  }
  Modint operator-() const { return (v ? Modint(Mod - v) : Modint(0)); }
  explicit operator int() const { return v; }
  explicit operator long long() const { return v; }
  Modint &operator+=(const Modint &a) {
    v = (v + a.v);
    if (v >= Mod) v -= Mod;
    return *this;
  }
  Modint &operator-=(const Modint &a) {
    v = (v - a.v);
    if (v < 0) v += Mod;
    return *this;
  }
  Modint &operator*=(const Modint &a) {
    v = (v * a.v) % Mod;
    return *this;
  }
  Modint &operator/=(const Modint &a) {
    v = (v * a.mpow(Mod - 2).v) % Mod;
    return *this;
  }
  template <class T>
  Modint &operator+=(const T &a) {
    v = (v + Modint(a).v);
    if (v >= Mod) v -= Mod;
    return *this;
  }
  template <class T>
  Modint &operator-=(const T &a) {
    v = (v - Modint(a).v);
    if (v < 0) v += Mod;
    return *this;
  }
  template <class T>
  Modint &operator*=(const T &a) {
    v = (v * Modint(a).v) % Mod;
    return *this;
  }
  template <class T>
  Modint &operator/=(const T &a) {
    v = (v * Modint(a).mpow(Mod - 2).v) % Mod;
    return *this;
  }
  friend Modint operator+(const Modint &a, const Modint &b) {
    return Modint(a) += b;
  }
  friend Modint operator-(const Modint &a, const Modint &b) {
    return Modint(a) -= b;
  }
  friend Modint operator*(const Modint &a, const Modint &b) {
    return Modint(a) *= b;
  }
  friend Modint operator/(const Modint &a, const Modint &b) {
    return Modint(a) /= b;
  }
  template <class T, class U>
  friend Modint operator+(const T &a, const U &b) {
    return Modint(a) += Modint(b);
  }
  template <class T, class U>
  friend Modint operator-(const T &a, const U &b) {
    return Modint(a) -= Modint(b);
  }
  template <class T, class U>
  friend Modint operator*(const T &a, const U &b) {
    return Modint(a) *= Modint(b);
  }
  template <class T, class U>
  friend Modint operator/(const T &a, const U &b) {
    return Modint(a) /= Modint(b);
  }
};

template <long long M>
ostream &operator<<(ostream &os, const Modint<M> m) {
  return os << m.v;
}
template <long long Mod = MOD>
class Factorial {
 private:
  int n;

 public:
  vector<long long> fac, inv;

 public:
  Factorial(long long n) : n(n), fac(n + 1), inv(n + 1) {
    fac[0] = 1;
    for (int i = 0; i < n; ++i) fac[i + 1] = fac[i] * (i + 1) % Mod;
    inv[n] = modpow(fac[n], Mod - 2);
    for (int i = n - 1; i >= 0; --i) inv[i] = inv[i + 1] * (i + 1) % Mod;
  };
  long long modpow(long long a, long long n, long long mod = Mod) {
    long long i = 1, ret = 1, p = a;
    while (i <= n) {
      if (i & n) {
        ret = (ret * p) % mod;
      }
      i = (i << 1);
      p = (p * p) % mod;
    }
    return ret;
  }
  long long C(int a, int b) {
    return (fac[a] * inv[b] % Mod) * inv[a - b] % Mod;
  }
  long long P(int a, int b) {
    return (fac[a]) * inv[a - b] % Mod;
  }
  long long H(int a, int b) {  //The number of multisets of length b on a symbols
    return C(a + b - 1, b);
  }
};

class Solver {
 public:
  int h, w, n;
  vector<pair<int, int>> rc;
  vector<vector<Modint<>>> dp;
  Factorial<> fac;
  Solver(LL h, LL w, LL n) : h(h), w(w), n(n), rc(n + 2), dp(n + 2, vector<Modint<>>(2)), fac(220000){};

  void solve() {
    for (int i = 1; i <= n; ++i) {
      cin >> rc[i].first >> rc[i].second;
    }
    rc[0] = {1, 1};
    rc[n + 1] = {h, w};
    sort(rc.begin(), rc.end(), [&](auto a, auto b) { return a.first + a.second < b.first + b.second; });
    dp[0][0] = Modint<>(1);
    for (int i = 1; i <= n + 1; ++i) {
      for (int j = 0; j < i; ++j) {
        //j-> i
        if (rc[i].first >= rc[j].first && rc[i].second >= rc[j].second) {
          dp[i][0] += dp[j][1] * fac.C(rc[i].first - rc[j].first + rc[i].second - rc[j].second, rc[i].first - rc[j].first);
          dp[i][1] += dp[j][0] * fac.C(rc[i].first - rc[j].first + rc[i].second - rc[j].second, rc[i].first - rc[j].first);
        }
      }
    }
    cout << dp[n + 1][1] - dp[n + 1][0] << endl;
  }
};  // namespace Problem

}  // namespace Problem

int main() {
  std::cin.tie(0);
  std::ios_base::sync_with_stdio(false);
  // std::cout << std::fixed << std::setprecision(12);
  long long n = 0, h, w;
  std::cin >> h >> w >> n;

  Problem::Solver sol(h, w, n);
  sol.solve();
  return 0;
}


Measured memory_bytes: 3840