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

#define NDEBUG
#include <cassert>


typedef long long ll;
typedef long double Double;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<llll> vllll;
typedef vector<bool> vb;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<long double> vD;

#define sz(a)  int((a).size())
#define pb  push_back
#define eb  emplace_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n)  for(int var=0;var<(n);++var)
#define rep1(var,n)  for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n)  for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define repC3(vari,varj,vark,n)  for(int vari=0;vari<(n)-2;++vari)for(int varj=vari+1;varj<(n)-1;++varj)for(int vark=varj+1;vark<(n);++vark)
#define ALL(c)  (c).begin(),(c).end()
#define RALL(c)  (c).rbegin(),(c).rend()
#define tr(i,c)  for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e)  ((s).find(e)!=(s).end())
#define mset(arr,val)  memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))
#define cons make_pair

template<class T> inline void amin(T & a, T const & b) { a = min(a, b); }
template<class T> inline void amax(T & a, T const & b) { a = max(a, b); }
template<typename X, typename T> auto vectors(X x, T a) { return vector<T>(x, a); }
template<typename X, typename Y, typename Z, typename... Zs> auto vectors(X x, Y y, Z z, Zs... zs) { auto cont = vectors(y, z, zs...); return vector<decltype(cont)>(x, cont); }


ll gcd(ll a, ll b) { while(a) swap(a, b%=a); return b; }

const ll MOD=1000000007LL;

ll ADD(ll x, ll y) { return (x+y) % MOD; }
ll SUB(ll x, ll y) { return (x-y+MOD) % MOD; }
ll MUL(ll x, ll y) { return x*y % MOD; }
ll POW(ll x, ll e) { ll v=1; for(; e; x=MUL(x,x), e>>=1) if (e&1) v = MUL(v,x); return v; }
ll DIV(ll x, ll y) { /*assert(y%MOD!=0);*/ return MUL(x, POW(y, MOD-2)); }

vector<ll> _fact;
void fact_init(int maxn){
    _fact.resize(maxn + 1);
    _fact[0] = _fact[1] = 1LL;
    for (int i=2; i<=maxn; ++i) _fact[i] = _fact[i-1] * i % MOD;
}
inline ll comb(int n, int k) {
    return DIV(_fact[n], MUL(_fact[n-k], _fact[k]));
}
inline ll pat_count(int dy, int dx) {
    return DIV(_fact[dy+dx], MUL(_fact[dy], _fact[dx]));
}

ll solve(int H,int W, int N, vi& r,vi& c) {
    int start=0, goal=N+1;

    fact_init(H+W);

    vvi reach(N+2);

    rep(i,N+2) rep(j,N+2) {
        if (i==j) continue;
        if (r[i] <= r[j] && c[i] <= c[j]) {
            reach[i].pb(j);
        }
    }

    vii order;
    rep(i,N+2) {
        order.emplace_back(r[i]+c[i], i);
    }
    sort(ALL(order));

    vector<vll> dp(N+2, vll(2, 0));
    dp[0][0] = 1;

    rep(i,N+2) {
        int u = order[i].second;
        for (int v: reach[u]) {
            ll mag = pat_count(r[v]-r[u], c[v]-c[u]);
            rep(parity, 2) {
                ll base = dp[u][parity];
                if (base == 0) continue;
                dp[v][1-parity] = ADD(dp[v][1-parity], MUL(dp[u][parity], mag));
            }
        }
    }

    ll ans = SUB(dp[goal][1], dp[goal][0]);
    return ans;
}

int main() {
    int H, W, N; scanf("%d%d%d", &H, &W, &N);
    vi r(N+2), c(N+2);
    r[0] = c[0] = 1;
    rep1(i,N){
        scanf("%d%d", &r[i], &c[i]);
    }
    r[N+1] = H; c[N+1] = W;

    cout << solve(H,W,N,r,c) << endl;
    return 0;
}


Measured memory_bytes: 26624