#include <bits/stdc++.h>

int ri() {
    int n;
    scanf("%d", &n);
    return n;
}
#define MOD 1000000007
template<int mod>
struct ModInt{
    int x;
    ModInt():x(0){}
    ModInt(long long y):x(y>=0?y%mod:(mod-(-y)%mod)%mod){}
    ModInt &operator+=(const ModInt &p){
        if((x+=p.x)>=mod)x-=mod;
        return *this;
    }
    ModInt &operator-=(const ModInt &p){
        if((x+=mod-p.x)>=mod)x-=mod;
        return *this;
    }
    ModInt &operator*=(const ModInt &p){
        x=(int)(1LL*x*p.x%mod);
        return *this;
    }
    ModInt &operator/=(const ModInt &p){
        *this*=p.inverse();
        return *this;
    }
	ModInt &operator^=(long long p){
		ModInt res = 1;
		for (; p; p >>= 1) {
			if (p & 1) res *= *this;
			*this *= *this;
		}
		return *this = res;
	}
    ModInt operator-()const{return ModInt(-x);}
    ModInt operator+(const ModInt &p)const{return ModInt(*this)+=p;}
    ModInt operator-(const ModInt &p)const{return ModInt(*this)-=p;}
    ModInt operator*(const ModInt &p)const{return ModInt(*this)*=p;}
    ModInt operator/(const ModInt &p)const{return ModInt(*this)/=p;}
	ModInt operator^(long long p)const{return ModInt(*this)^=p;}
    bool operator==(const ModInt &p)const{return x==p.x;}
    bool operator!=(const ModInt &p)const{return x!=p.x;}
    explicit operator int() const { return x; }                           // added by QCFium
    ModInt operator=(const int p) {x = p; return ModInt(*this);} // added by QCFium
    ModInt inverse()const{
        int a=x,b=mod,u=1,v=0,t;
        while(b>0){
            t=a/b;
            a-=t*b;
            std::swap(a,b);
            u-=t*v;
            std::swap(u,v);
        }
        return ModInt(u);
    }
    friend std::ostream &operator<<(std::ostream &os,const ModInt<mod> &p){
        return os<<p.x;
    }
    friend std::istream &operator>>(std::istream &is,ModInt<mod> &a){
        long long x;
        is>>x;
        a=ModInt<mod>(x);
        return (is);
    }
};
typedef ModInt<MOD> mint;

struct MComb {
    std::vector<mint> fact;
    std::vector<mint> inversed;
    MComb(int n) { // O(n+log(mod))
        fact = std::vector<mint>(n+1,1);
        for (int i = 1; i <= n; i++) fact[i] = fact[i-1]*mint(i);
        inversed = std::vector<mint>(n+1);
        inversed[n] = fact[n] ^ (MOD-2);
        for (int i = n - 1; i >= 0; i--) inversed[i]=inversed[i+1]*mint(i+1);
    }
    mint ncr(int n, int r) {
        return (fact[n] * inversed[r] * inversed[n-r]);
    }
    mint npr(int n, int r) {
        return (fact[n] * inversed[n-r]);
    }
    mint nhr(int n, int r) {
        assert(n+r-1 < (int)fact.size());
        return ncr(n+r-1, r);
    }
};

int main() {
	int h = ri(), w = ri(), n = ri();
	std::pair<int, int> a[n];
	for (int i = 0; i < n; i++) a[i].first = ri() - 1, a[i].second = ri() - 1;
	std::sort(a, a + n);
	MComb com(h + w + 1);
	auto michi = [&] (int x, int y) { return com.ncr(x + y, x); };
	mint dp[n];
	for (int i = 0; i < n; i++) {
		dp[i] = michi(a[i].first, a[i].second);
		for (int j = 0; j < i; j++) {
			if (a[j].first <= a[i].first && a[j].second <= a[i].second) {
				dp[i] -= dp[j] * michi(a[i].first - a[j].first, a[i].second - a[j].second);
			}
		}
	}
	mint res = michi(h - 1, w - 1);
	for (int i = 0; i < n; i++) res -= dp[i] * michi(h - 1 - a[i].first, w - 1 - a[i].second);
	std::cout << res << std::endl;
    return 0;
}


Measured memory_bytes: 1792