#include <bits/stdc++.h>
using namespace std;

#define rep(i,m,n) for(int (i)=(int)(m);i<(int)(n);i++)
#define rep2(i,m,n) for(int (i)=(int)(n)-1;i>=(int)(m);i--)
#define REP(i,n) rep(i,0,n)
#define REP2(i,n) rep2(i,0,n)
#define FOR(i,c) for(decltype((c).begin())i=(c).begin();i!=(c).end();++i)
#define all(hoge) (hoge).begin(),(hoge).end()
#define en '\n'
using ll = long long;
using ull = unsigned long long;
template <class T> using vec = vector<T>;
template <class T> using vvec = vector<vec<T>>;
typedef pair<ll, ll> P;
constexpr long long INF = 1LL << 60;
constexpr int INF_INT = 1 << 25;
constexpr long long MOD = (ll) 1e9 + 7;
//constexpr long long MOD = 998244353LL;
typedef vector<ll> Array;
typedef vector<Array> Matrix;


template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

struct Edge {
	ll to, cap, rev;
	Edge(ll _to, ll _cap, ll _rev) {
	to = _to; cap = _cap; rev = _rev;
	}
};
using Edges = vector<Edge>;
using Graph = vector<Edges>;

void add_edge(Graph& G, ll from, ll to, ll cap, bool revFlag, ll revCap) {
	G[from].push_back(Edge(to, cap, (ll)G[to].size()));
	if (revFlag)G[to].push_back(Edge(from, revCap, (ll)G[from].size() - 1));
}

// modint (1000000007 で割ったあまりを扱う構造体)
template<int MOD> struct Fp {
    long long val;
    constexpr Fp(long long v = 0) noexcept : val(v % MOD) {
        if (val < 0) v += MOD;
    }
    constexpr int getmod() { return MOD; }
    constexpr Fp operator - () const noexcept {
        return val ? MOD - val : 0;
    }
    constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; }
    constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; }
    constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; }
    constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; }
    constexpr Fp& operator += (const Fp& r) noexcept {
        val += r.val;
        if (val >= MOD) val -= MOD;
        return *this;
    }
    constexpr Fp& operator -= (const Fp& r) noexcept {
        val -= r.val;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr Fp& operator *= (const Fp& r) noexcept {
        val = val * r.val % MOD;
        return *this;
    }
    constexpr Fp& operator /= (const Fp& r) noexcept {
        long long a = r.val, b = MOD, u = 1, v = 0;
        while (b) {
            long long t = a / b;
            a -= t * b; swap(a, b);
            u -= t * v; swap(u, v);
        }
        val = val * u % MOD;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr bool operator == (const Fp& r) const noexcept {
        return this->val == r.val;
    }
    constexpr bool operator != (const Fp& r) const noexcept {
        return this->val != r.val;
    }
    friend constexpr ostream& operator << (ostream &os, const Fp<MOD>& x) noexcept {
        return os << x.val;
    }
    friend constexpr istream& operator >> (istream &is, Fp<MOD>& x) noexcept {
        return is >> x.val;
    }
    friend constexpr Fp<MOD> modpow(const Fp<MOD> &a, long long n) noexcept {
        if (n == 0) return 1;
        auto t = modpow(a, n / 2);
        t = t * t;
        if (n & 1) t = t * a;
        return t;
    }
};
using mint = Fp<MOD>;

// 二項係数ライブラリ
template<class T> struct Combination {
    vector<T> fact_, inv_, finv_;
    constexpr Combination() {}
    constexpr Combination(int n) noexcept : fact_(n, 1), inv_(n, 1), finv_(n, 1) {
        init(n+1);
    }
    constexpr void init(int n) noexcept {
        fact_.assign(n, 1), inv_.assign(n, 1), finv_.assign(n, 1);
        int MOD = fact_[0].getmod();
        for(int i = 2; i < n; i++){
            fact_[i] = fact_[i-1] * i;
            inv_[i] = -inv_[MOD%i] * (MOD/i);
            finv_[i] = finv_[i-1] * inv_[i];
        }
    }
    constexpr T nPr(int n, int k) const noexcept {
        if (n < k || n < 0 || k < 0) return 0;
        return fact_[n] * finv_[n-k];
    }
    constexpr T nCr(int n, int k) const noexcept {
        if (n < k || n < 0 || k < 0) return 0;
        return fact_[n] * finv_[k] * finv_[n-k];
    }
    constexpr T nHr(int n, int k) const noexcept {
        if (n < k || n < 0 || k < 0) return 0;
        return nCr(n+k-1,k);
    }
    constexpr T fact(int n) const noexcept {
        if (n < 0) return 0;
        return fact_[n];//n!
    }
    constexpr T inv(int n) const noexcept {
        if (n < 0) return 0;
        return inv_[n];//1/n
    }
    constexpr T finv(int n) const noexcept {
        if (n < 0) return 0;
        return finv_[n];//1/n!
    }
};


void solve(){
    ll h,w,n;
    cin>>h>>w>>n;
    vec<P> rc(n+1);
    rc[n]={h,w};
    REP(i,n) cin>>rc[i].first>>rc[i].second;
    sort(all(rc));

    Combination<mint> com(h+w);

    auto d=[&](ll x,ll y){
        return com.nCr(x+y,y);//(0,0)->(x,y)の経路
    };

    vec<mint> dp(n+1,0);

    REP(i,n+1){
        dp[i]=d(rc[i].first-1,rc[i].second-1);
        REP(j,i){
            if(rc[j].first>rc[i].first || rc[j].second>rc[i].second) continue;
            dp[i]-=dp[j]*d(rc[i].first-rc[j].first,rc[i].second-rc[j].second);
        }
    }
    cout<<dp[n]<<en;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    solve();
    //ll t;cin>>t;REP(i,t) solve();

    return 0;
}

Measured memory_bytes: 6628