/*
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　　　ノヽ
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　　 UU
*/
#pragma region macro
#include <iostream>
#include<queue>
#include<stack>
#include<vector>
#include<set>
#include<map>
#include<algorithm>
#include<cstring>
#include<string>
#include<cassert>
#include<cmath>
#include<climits>
#include<iomanip>
#include<bitset>
#include<unordered_map>
typedef long long int64;
using namespace std;
using P = pair<int64, int64>;
typedef vector<int> vi;
const int MOD = (int)1e9 + 7;
const int64 INF = 1LL << 62;
const int inf = 1<<30;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
#define REP(i, n) for (int i = 0; i < (n); i++)
#define FOR(i,s,n) for (int i = s; i < (n); i++)
#define ALL(obj) (obj).begin(), (obj).end() //コンテナじゃないと使えない!!
#define debug(x) cerr << #x << ": " << x << "\n";
#define mp make_pair
#define bn '\n'
template <typename T>
ostream& operator<<(ostream& os, const vector<T> &V){
    int N = V.size();
    REP(i,N){
        os << V[i];
        if (i!=N-1) os << " ";
    }
    os << "\n";
    return os;
}
template <typename T,typename S>
ostream& operator<<(ostream& os, pair<T,S> const&P){
    os << "(";
    os << P.first;
    os << " , ";
    os << P.second;
    os << ")";
    return os;
}
template <typename T>
ostream& operator<<(ostream& os, set<T> &S){
    auto it=S.begin();
    while(it!=S.end()){
        os << *it;
        os << " ";
        it++;
    }
    os << "\n";
    return os;
}
template <typename T>
ostream& operator<<(ostream& os, deque<T> &q){
    for(auto it=q.begin();it<q.end();it++){
        os<<*it;
        os<<" ";
    }
     os<<endl;
    return os;
}
vector<pair<int,int>> dxdy = {mp(0,1),mp(1,0),mp(-1,0),mp(0,-1)};
#pragma endregion
//fixed<<setprecision(10)<<ans<<endl;

int64 pow(int a,int b,int mod){
    vector<bool> bit;
    for(b=b;b>0;b>>=1){
        bit.push_back(b&1);
    }
    vector<int64> fac(bit.size()); fac[0] = a;
    int64 res = 1;
    for(int i=1;i<bit.size();i++){
        fac[i] = (fac[i-1] * fac[i-1])%mod;
    }
    for(int i=0;i<bit.size();i++){
        if(bit[i]) res*=fac[i];
        res%=mod;
    }
    return res;
}


//mint
struct mint {
    int64 x;
    mint(int64 x=0):x((x+2*MOD)%MOD){}
    mint& operator+=(const mint a) {
        if ((x += a.x) >= MOD) x -= MOD;
        return *this;
    }
    mint& operator-=(const mint a) {
        if ((x += MOD-a.x) >= MOD) x -= MOD;
        return *this;
    }
    mint& operator*=(const mint a) {
        (x *= a.x) %= MOD;
        return *this;
    }
    mint operator+(const mint a) const {
        mint res(*this);
        return res+=a;
    }
    mint operator-(const mint a) const {
        mint res(*this);
        return res-=a;
    }
    mint operator*(const mint a) const {
        mint res(*this);
        return res*=a;
    }
    mint pow(int64 t) const {
        if (!t) return 1;
        mint a = pow(t>>1);
        a *= a;
        if (t&1) a *= *this;
        return a;
    }

    // for prime MOD
    mint inv() const {
        return pow(MOD-2);
    }
    mint& operator/=(const mint a) {
        return (*this) *= a.inv();
    }
    mint operator/(const mint a) const {
        mint res(*this);
        return res/=a;
    }
};
ostream& operator<<(ostream& os, mint a){
    os << a.x;
    return os;
}

class BigCombination{
private:
    const int MAX = 510'000;
    mint fac[510000], inv[510000];
public:
    BigCombination(){
        fac[0] = fac[1] = 1;
        for(int i=2; i<MAX; i++){
            fac[i] = fac[i-1] * i;
        }
        inv[MAX-1] = fac[MAX-1].inv();
        for(int i=MAX-1;i>0;i--){
            inv[i-1] = inv[i] * i;
        }
    }

    mint combination(int n,int r){
        if(n<r) return 0;
        if(n<0 || r<0) return 0;
        if(n==r) return 1;
        return fac[n] * inv[r] * inv[n-r];
    }
};

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int H,W,N;
    cin >> H >> W >> N;

    BigCombination B;
    // mint ans=B.get;
    vector<vector<mint>> DP(N,vector<mint>(2,0)); //DP[i][偶奇]:iまで(偶奇)個使った場合の数
    vector<pair<int,int>> HW;
    int h,w;
    REP(i,N){
        cin >> h >> w;
        HW.emplace_back(h,w);
    }

    sort(ALL(HW));
    REP(i,N){
        tie(h,w) = HW[i];
        DP[i][1] = B.combination(h+w-2,w-1);
    }

    REP(i,N){
        for(int j=i+1;j<N;j++){
            h = HW[j].first - HW[i].first;
            w = HW[j].second - HW[i].second;
            if(w<0) continue;
            DP[j][1] += DP[i][0] * B.combination(h+w,w);
            DP[j][0] += DP[i][1] * B.combination(h+w,w);
        }
    }

    mint ans = B.combination(H+W-2,W-1);
    REP(i,N){
        h = H - HW[i].first ;
        w = W - HW[i].second;
        ans += DP[i][0] * B.combination(h+w,w);
        ans -= DP[i][1] * B.combination(h+w,w);
    }
    cout << ans << bn;


}

Measured memory_bytes: 8448