#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define EB emplace_back
#define MP make_pair
#define all(o) (o).begin(), (o).end()
#define mset(m,v) memset(m,v,sizeof(m))
#define fr(i,n) for(lli i=0;i<n;++i)
#define rep(i,a,b) for(lli i=a;i<=b;++i)
#define per(i,a,b) for(lli i=a;i>=b;i--)
#define remin(a,b) (a=min((a),(b)))
#define remax(a,b) (a=max((a),(b))) 
#define sz(x) (lli)(x).size()
#define endl '\n'
typedef long long lli;        typedef long double ld;
typedef pair<lli,lli> ii;     typedef vector<lli> vi;
typedef vector<ii> vii;       typedef vector<vi> graph;
long long MOD=1000000007;     long double EPS=1e-9;
#define debarr(a,n) cout<<#a<<" : ";for(int i=0;i<n;i++) cerr<<a[i]<<" "; cerr<<endl;
#define debmat(mat,row,col) cout<<#mat<<" :\n";for(int i=0;i<row;i++) {for(int j=0;j<col;j++) cerr<<mat[i][j]<<" ";cerr<<endl;}
#define pr(...) dbs(#__VA_ARGS__, __VA_ARGS__)
template <class S, class T>ostream& operator <<(ostream& os, const pair<S, T>& p) {return os << "(" << p.first << ", " << p.second << ")";}
template <class T>ostream& operator <<(ostream& os, const vector<T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class T>ostream& operator <<(ostream& os, const unordered_set<T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class S, class T>ostream& operator <<(ostream& os, const unordered_map<S, T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class T>ostream& operator <<(ostream& os, const set<T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class T>ostream& operator <<(ostream& os, const multiset<T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class S, class T>ostream& operator <<(ostream& os, const map<S, T>& p) {os << "[ "; for (auto& it : p) os << it << " "; return os << "]";}
template <class T> void dbs(string str, T t) {cerr << str << " : " << t << "\n";}
template <class T, class... S> void dbs(string str, T t, S... s) {int idx = str.find(','); cerr << str.substr(0, idx) << " : " << t << ","; dbs(str.substr(idx + 1), s...);}
template <class T> void prc(T a, T b) {cerr << "["; for (T i = a; i != b; ++i) {if (i != a) cerr << ", "; cerr << *i;} cerr << "]\n";}
lli binpow(lli b,lli p,lli mod){lli ans=1;b%=mod;for(;p;p>>=1){if(p&1)ans=ans*b%mod;b=b*b%mod;}return ans;}

#define MAXN 2000100
lli fact[MAXN];
lli factinv[MAXN];
lli pow2[MAXN];
void pre(){
    fact[0]=1;
    rep(i,1,MAXN-1){
        fact[i]=(fact[i-1]*i)%MOD;
    }
    //pow2[0]=1;
    //rep(i,1,MAXN-1)pow2[i]=pow2[i-1]*2%MOD;
    factinv[0]=1;
    factinv[1]=1;
    rep(i,2,MAXN-1){
        factinv[i]=((-1*(MOD/i)*factinv[MOD%i])%MOD+MOD)%MOD;
    }
    rep(i,1,MAXN-1){
        factinv[i]=factinv[i]*factinv[i-1]%MOD;
    }
}
lli ncr(lli n,lli r){
    if(r<0||r>n)return 0;
    return (fact[n]*(factinv[n-r]*factinv[r]%MOD))%MOD;
}

lli ways(lli x1,lli y1,lli x2,lli y2){
	if(x2<x1||y2<y1)return 0;
	return ncr((x2-x1)+(y2-y1),(x2-x1));
}

bool cmp(ii aa,ii bb){
	return aa.F+aa.S<bb.F+bb.S;
}

vii arr;

void solve(){
	lli h,w,n;
	cin>>h>>w>>n;
	fr(i,n){
		int a,b;
		cin>>a>>b;
		arr.EB(a,b);
	}
	arr.EB(1,1);
	arr.EB(h,w);
	sort(all(arr),cmp);	
	lli nn=arr.size();
	lli dp[nn];
	dp[0]=1;
	//pr(arr);
	rep(i,1,nn-1){
		dp[i]=ways(arr[0].F,arr[0].S,arr[i].F,arr[i].S)%MOD;
		rep(j,1,i-1){
			//pr(i,j);
			dp[i]=(dp[i]-(dp[j]*ways(arr[j].F,arr[j].S,arr[i].F,arr[i].S)%MOD)+MOD)%MOD;
		}
	}
	cout<<dp[nn-1]<<endl;
}

signed main(){
	ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	//freopen("in.txt","r",stdin);//freopen("out.txt","w",stdout);
	pre();lli t=1;//cin>>t;
	for(lli i=1;i<=t;i++){
		//cout<<"Case #"<<i<<": ";
		solve();
	}
}

Measured memory_bytes: 33024