#include<stdio.h>
#include<vector>
#include<algorithm>
using namespace std;
typedef long long ll;
ll mod = 1000000007;
#define SIZE 1000000
ll inv[SIZE + 1];
ll kai[SIZE + 1];
ll invkai[SIZE + 1];
void invinit()
{
	inv[1] = 1;
	for (int i = 2; i <= SIZE; i++)
	{
		inv[i] = mod - (mod / i)*inv[mod%i] % mod;
	}
	kai[0] = invkai[0] = 1;
	for (int i = 1; i <= SIZE; i++)
	{
		kai[i] = kai[i - 1] * i%mod;
		invkai[i] = invkai[i - 1] * inv[i] % mod;
	}
}
ll com(ll a, ll b)
{
	if (b < 0 || a < b)return 0;
	return (invkai[b] * invkai[a - b]) % mod*kai[a] % mod;
}
ll p2[1000001];
int main()
{
	invinit();
	ll n, m, k;
	scanf("%lld%lld%lld", &n, &m, &k);
	p2[0] = 1;
	for (int i = 1; i <= 1000000; i++)p2[i] = p2[i - 1] * 2 % mod;
	ll nm = 0, nk = 0;
	for (int i = n; i <= n + m; i++)nm = (nm + com(n + m, i)) % mod;
	for (int i = n; i <= n + k; i++)nk = (nk + com(n + k, i)) % mod;
	ll ans = 0;
	for (int s = 0; s <= k; s++)
	{
		ans += p2[k - s] * nm%mod*com(n + m + k, s) % mod;
		ans %= mod;
	}
	for (int s = 0; s <= m; s++)
	{
		ans += p2[m - s] * nk%mod*com(n + m + k, s) % mod;
		ans %= mod;
	}
	ll now = 0;
	for (int t = 0; t <= k; t++)
	{
		now += com(n + m + k - m, t);
		now %= mod;
	}
	for (int s = m; s >= 0; s--)
	{
		ans += mod - (now*com(n + m + k, s) % mod);
		ans %= mod;
		now = (now * 2 + mod - com(n + m + k - s, k));
		now %= mod;
	}
	printf("%lld\n", ans);
}