#include"bits/stdc++.h"
using namespace std;
#define REP(k,m,n) for(int (k)=(m);(k)<(n);(k)++)
#define rep(i,n) REP((i),0,(n))
using ll = long long;

struct ModInt {
	static const ll MOD = 1000000007;

	// constructors etc
	ModInt() :num(1ll) {}
	ModInt(ll num_) :num(num_%MOD) {}
	ModInt(const ModInt& modint) :num(modint.num%MOD) {}
	ll get()const { return num; }

	// operator etc
	// operator ll() const { return num; }
	// ll operator*() { return num; }
	ModInt& operator+=(const ModInt& r) { (num += r.num) %= MOD; return *this; }
	ModInt& operator-=(const ModInt& r) { (num += -r.num + MOD) %= MOD; return *this; }
	ModInt& operator*=(const ModInt& r) { (num *= r.num) %= MOD; return *this; }
	ModInt& operator/=(const ModInt& r) { (num *= r.inv().num) %= MOD; return *this; }
	ModInt pow(const ModInt& r)const {
		ll res = 1;
		ll x = num;
		ll n = r.num;
		while (n > 0) {
			if (n & 1)res = (res*x) % MOD;
			x = (x*x) % MOD;
			n >>= 1;
		}
		return res;
	}
	ModInt inv()const { return this->pow(MOD - 2); }

	ModInt operator+(const ModInt& r)const { return ModInt(*this) += r; }
	ModInt operator-(const ModInt& r)const { return ModInt(*this) -= r; }
	ModInt operator*(const ModInt& r)const { return ModInt(*this) *= r; }
	ModInt operator/(const ModInt& r)const { return ModInt(*this) /= r; }
	ModInt operator+(const ll& r)const { return *this + ModInt(r); }
	ModInt operator-(const ll& r)const { return *this - ModInt(r); }
	ModInt operator*(const ll& r)const { return *this * ModInt(r); }
	ModInt operator/(const ll& r)const { return *this / ModInt(r); }

private:
	ll num;
};
ostream& operator<<(ostream& stream, const ModInt& val) { stream << val.get(); return stream; }

struct Comb {
	static constexpr ll LIM = 310000;
	static vector<ModInt> fact, inv;

	static void init() {
		fact.resize(LIM, 1);
		inv.resize(LIM, 1);

		REP(i, 1, LIM)fact[i] = fact[i - 1] * i;
		inv[LIM - 1] = fact[LIM - 1].inv();
		for (ll i = LIM - 2; i > 0; i--)inv[i] = inv[i + 1] * (i + 1);
	}

	static ll comb(ll n, ll k) {
		if (n < k)return 0ll;
		return (fact[n] * inv[k] * inv[n - k]).get();
	}
};
vector<ModInt> Comb::fact;
vector<ModInt> Comb::inv;

int main()
{
	ll a, b, c;
	cin >> a >> b >> c;
	ll total = a + b + c;

	Comb::init();

	ModInt res(0);
	REP(i, 1, a + 1) {
		ll na = a - i;
		ll nb = b - 1;
		ll nc = c;
		ll ntotal = na + nb + nc;
		auto tres = ModInt(2).pow(ntotal) - 1;
		nc--; ntotal--;
		tres *= Comb::fact[ntotal];
		tres *= Comb::inv[na];
		tres *= Comb::inv[nb];
		tres *= Comb::inv[nc];
		res += tres;
	}
	cout << res.get() << endl;
	return 0;
}