#include <bits/stdc++.h>
#define MOD (long long)(1e9 + 7)
#define MAX 500000
using namespace std;

template <int mod>
struct ModInt {
  int x;
  ModInt() : x(0) {}
  ModInt(int64_t y)
      : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
  ModInt &operator+=(const ModInt &p) {
    if((x += p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt &operator-=(const ModInt &p) {
    if((x += mod - p.x) >= mod) 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;
  }
  bool operator==(const ModInt &p) const {
    return x == p.x;
  }
  bool operator!=(const ModInt &p) const {
    return x != p.x;
  }
  ModInt inverse() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while(b > 0) {
      t = a / b;
      swap(a -= t * b, b);
      swap(u -= t * v, v);
    }
    return ModInt(u);
  }
  ModInt pow(int64_t n) const {
    ModInt ans(1), mul(x);
    while(n) {
      if(n & 1) ans *= mul;
      mul *= mul;
      n >>= 1;
    }
    return ans;
  }
  friend ostream &operator<<(ostream &os, const ModInt &p) {
    return os << p.x;
  }
  friend istream &operator>>(istream &is, ModInt &a) {
    int64_t t;
    is >> t;
    a = ModInt<mod>(t);
    return (is);
  }
  static int get_mod() { return mod; }
};

struct Combination {
  vector<ModInt<MOD>> _fact, _rfact, _inv;
  Combination(long long nsize = 500000)
      : _fact(nsize + 1), _rfact(nsize + 1),
        _inv(nsize + 1) {
    _fact[0] = _rfact[nsize] = _inv[0] = 1;
    for(int i = 1; i <= nsize; i++)
      _fact[i] = _fact[i - 1] * i;
    _rfact[nsize] /= _fact[nsize];
    for(int i = nsize - 1; i >= 0; i--)
      _rfact[i] = _rfact[i + 1] * (i + 1);
    for(int i = 1; i <= nsize; i++)
      _inv[i] = _rfact[i] * _fact[i - 1];
  }
  inline ModInt<MOD> fact(int k) const { return _fact[k]; }

  inline ModInt<MOD> rfact(int k) const {
    return _rfact[k];
  }

  inline ModInt<MOD> inv(int k) const { return _inv[k]; }

  ModInt<MOD> P(int n, int r) const {
    if(r < 0 || n < r) return 0;
    return fact(n) * rfact(n - r);
  }

  ModInt<MOD> C(int p, int q) const {
    if(q < 0 || p < q) return 0;
    return fact(p) * rfact(q) * rfact(p - q);
  }
  ModInt<MOD> H(int n, int r) const {
    if(n < 0 || r < 0) return (0);
    return r == 0 ? 1 : C(n + r - 1, r);
  }
};

struct data {
  long long r, c;
};
bool operator<(const data &l, const data &r) {
  if(l.r != r.r) return l.r < r.r;
  return l.c < r.c;
}

long long n, h, w;
Combination comb;
vector<data> v;
ModInt<MOD> dp[3005][2];

ModInt<MOD> solve();

int main() {
  cin >> h >> w >> n;
  v.resize(n);
  for(int i = 0; i < n; ++i) cin >> v[i].r >> v[i].c;
  cout << solve() << endl;
  return 0;
}

ModInt<MOD> solve() {
  comb = Combination(MAX);
  v.push_back({h, w});
  v.push_back({1, 1});
  sort(v.begin(), v.end());
  n += 2;
  for(int i = 0; i < n; ++i) --v[i].r, --v[i].c;
  dp[0][0] = 1;
  for(int i = 1; i < n; ++i)
    for(int j = 0; j < 2; ++j)
      for(int k = 0; k < i; ++k)
        if(v[i].c >= v[k].c) {
          dp[i][j] +=
              dp[k][1 - j] *
              comb.C(v[i].r + v[i].c - v[k].r - v[k].c,
                     v[i].r - v[k].r);
        }
  return dp[n - 1][1] - dp[n - 1][0];
}

Measured memory_bytes: 12032