#include <iostream>
#include <vector>
#include <algorithm>
#define llint long long
#define mod 1000000007

using namespace std;

const int FACT_MAX = 300005;
llint fact[FACT_MAX], fact_inv[FACT_MAX];

llint modpow(llint a, llint n)
{
	if(n == 0) return 1;
	if(n % 2){
		return ((a%mod) * (modpow(a, n-1)%mod)) % mod;
	}
	else{
		return modpow((a*a)%mod, n/2) % mod;
	}
}

void make_fact()
{
	llint val = 1;
	fact[0] = 1;
	for(int i = 1; i < FACT_MAX; i++){
		val *= i;
		val %= mod;
		fact[i] = val;
	}
	fact_inv[FACT_MAX-1] = modpow(fact[FACT_MAX-1], mod-2);
	for(int i = FACT_MAX-2; i >= 0; i--){
		fact_inv[i] = fact_inv[i+1] * (i+1) % mod;
	}
}

llint comb(llint n, llint k)
{
	if(n == -1) return 1;
	llint ret = 1;
	ret *= fact[n];
	ret *= fact_inv[k], ret %= mod;
	ret *= fact_inv[n-k], ret %= mod;
	return ret;
}

llint a, b, c;
llint beki[300005], sum[300005];

int main(void)
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	make_fact();
	
	cin >> a >> b >> c;
	int n = a+b+c;
	
	beki[0] = 1;
	for(int i = 1; i <= n; i++) beki[i] = beki[i-1] * 2, beki[i] %= mod;
	sum[0] = beki[0];
	for(int i = 1; i <= n; i++) sum[i] = sum[i-1] + beki[i], sum[i] %= mod;
	
	llint ans = 0;
	for(int i = c-1; i < n-2; i++){
		llint tmp = 0;
		if(c >= 2 && i >= 1) tmp += comb(i-1, c-2) * sum[i-1] % mod, tmp %= mod;
		tmp += comb(i, c-1) * beki[i] % mod, tmp %= mod;
		llint mul = comb(a+b, a);
		if(i-(c-1)>= a) mul += mod - comb(i-(c-1), a), mul %= mod;
		if(i-(c-1)>= b) mul += mod - comb(i-(c-1), b), mul %= mod;
		tmp *= mul, tmp %= mod;
		ans += tmp, ans %= mod;
	}
	ans *= modpow(2, mod-2), ans %= mod;
	cout << ans << endl;
	
	return 0;
}