#include <bits/stdc++.h>
using namespace std;
#define int long long
#define stoi stoll
using ll=long long;
using vi=vector<int>;
using pii=pair<int,int>;
#define ALL(c) begin(c),end(c)
#define RALL(c) rbegin(c),rend(c)
#define ITR(i,b,e) for(auto i=(b);i!=(e);++i)
#define FORE(x,c) for(auto &&x:c)
#define REPF(i,a,n) for(int i=a,i##len=(int)(n);i<i##len;++i)
#define REP(i,n) REPF(i,0,n)
#define REPR(i,n) for(int i=(int)(n);i>=0;--i)
#define SZ(c) ((int)c.size())
#define CONTAIN(c,x) (c.find(x)!=end(c))
#define INSEG(l,x,r) ((l)<=(x)&&(x)<(r))
#define dump(...)
#define pb push_back
#define _ 0
const signed INF_=1001001001; const long long INF=1001001001001001001LL;
const int DX[9]={0,1,0,-1,1,1,-1,-1,0},DY[9]={-1,0,1,0,-1,1,1,-1,0};
template<class T> ostream& operator<<(ostream &os,const vector<T> &v) {
    ITR(i,begin(v),end(v))os<<*i<<(i==end(v)-1?"":" ");return os;}
template<class T> istream& operator>>(istream &is,vector<T> &v) {
    ITR(i,begin(v),end(v)) is>>*i;return is;}
template<class T,class U> istream& operator>>(istream &is, pair<T,U> &p) {
    is>>p.first>>p.second;return is;}
template<class T, class U> bool chmax(T &a,const U &b){return a<b?a=b,1:0;}
template<class T, class U> bool chmin(T &a,const U &b){return a>b?a=b,1:0;}
template <class T> void PSUM(T& c) {partial_sum(begin(c), end(c), begin(c));}
template<class T> using heap=priority_queue<T,vector<T>,greater<T>>;
struct before_main_function {
    before_main_function() {
        cin.tie(0); ios::sync_with_stdio(false);
        cout << setprecision(15) << fixed;
        #define endl "\n"
    }
} before_main_function;
//------------------8<------------------------------------8<--------------------

template <int mod = 1000000007>
class ModInt {
public:
    ModInt() : v(0) {}
    ModInt(int x) : v((x+mod)%mod) {}
    int value() const {return v;}
    const ModInt operator+(const ModInt &r) const { return ModInt(this->v + r.v); }
    const ModInt operator-(const ModInt &r) const { return ModInt(this->v + mod - r.v); }
    const ModInt operator*(const ModInt &r) const { return ModInt(this->v * r.v); }
    const ModInt operator/(const ModInt &r) const { return (*this * (~r)); }
    const ModInt operator~() const { return ModInt(bpow(this->v, mod-2)); }
    bool operator==(const ModInt &r) const { return this->v == r.v; }
    bool operator!=(const ModInt &r) const { return this->v != r.v; }
    ModInt& operator+=(const ModInt &r) { return *this = *this + r; }
    ModInt& operator-=(const ModInt &r) { return *this = *this - r; }
    ModInt& operator*=(const ModInt &r) { return *this = *this * r; }
    ModInt& operator/=(const ModInt &r) { return *this = *this * (~r); }
private:
    int v;
    int bpow(int a, int b) const {
        int ret = 1;
        while (b > 0) {
            if (b & 1) ret = (ret * a) % mod;
            a = (a * a) % mod;
            b >>= 1;
        }
        return ret;
    }
};
using Mint = ModInt<>;

struct Factorial {
    static constexpr int MAX_N = 2000006;
    vector<Mint> fact, fact_inv;
    Factorial(size_t size = MAX_N) : fact(size), fact_inv(size) {
        fact[0] = fact_inv[0] = 1;
        for (int i = 1; i < MAX_N; ++i) {
            fact[i] = fact[i - 1] * i;
            fact_inv[i] = ~fact[i];
        }
    }
    Mint cobmination(int N, int R) {
        if (N < R) return 0;
        return fact[N] * fact_inv[N - R] * fact_inv[R];
    }
    static Mint bin_pow(Mint x, int p) {
        if (x.value() == 0) return x;
        Mint prod = 1;
        while (p > 0) {
            if (p & 1) prod *= x;
            x *= x;
            p >>= 1;
        }
        return prod;
    }
};
// MAX_N 注意！

signed main() {
    int H, W, N;
    cin >> H >> W >> N;
    vector<pii> p(N);
    cin >> p;
    FORE(x, p) x.first--, x.second--;

    p.push_back({H - 1, W - 1});
    N++;

    vector<int> deg(N);
    vector<vector<int>> g(N), ginv(N);
    REP(i, N) {
        REP(j, N) {
            if (i == j) continue;
            if (p[i].first <= p[j].first && p[i].second <= p[j].second) {
                deg[j]++;
                g[i].push_back(j);
                ginv[j].push_back(i);
            }
        }
    }

    vector<int> sorted;
    {
        sorted.reserve(N);
        stack<int> st;
        REP(i, N) if (deg[i] == 0) st.push(i);
        while (!st.empty()) {
            int v = st.top(); st.pop();
            sorted.push_back(v);
            FORE(w, g[v]) {
                deg[w]--;
                if (deg[w] == 0) st.push(w);
            }
        }
    }

    vector<Mint> dp(N);
    Factorial fact;
    FORE(v, sorted) {
        dp[v] = fact.cobmination(p[v].first + p[v].second, p[v].first);
        FORE(w, ginv[v]) {
            int dx = p[v].first - p[w].first;
            int dy = p[v].second - p[w].second;
            dp[v] -= dp[w] * fact.cobmination(dx + dy, dx);
        }
    }

    cout << dp.back().value() << endl;
    return (0^_^0);
}



Measured memory_bytes: 122752