#include <iostream>
using namespace std;

long long modpow(long long a, long long b, long long m) {
	long long p = 1, q = a;
	for (int i = 0; i < 30; i++) {
		if ((b &(1LL << i)) != 0) { p *= q; p %= m; }
		q *= q; q %= m;
	}
	return p;
}

long long Div(long long a, long long b, long long m) {
	return (a * modpow(b, m - 2, m)) % m;
}

long long mod = 1000000007;
long long fact[300009], factinv[300009], inv[300009], power2[300009];
long long A, B, C;

void init() {
	fact[0] = 1;
	for (int i = 1; i <= 300000; i++) fact[i] = (1LL * i * fact[i - 1]) % mod;
	for (int i = 0; i <= 300000; i++) factinv[i] = Div(1, fact[i], mod);
	for (int i = 1; i <= 300000; i++) inv[i] = Div(1, i, mod);

	power2[0] = 1;
	for (int i = 1; i <= 300000; i++) power2[i] = (2LL * power2[i - 1]) % mod;
}

long long ncr(long long n, long long r) {
	if (n < r || r < 0) return 0LL;
	return (fact[n] * factinv[r] % mod) * factinv[n - r] % mod;
}

int main() {
	init();
	cin >> A >> B >> C;

	// Y の合計を求める
	long long Y = 0, TotalWays = 0;
	for (int i = 1; i <= A; i++) {
		long long Y1 = power2[A + B + C - i - 1] - 1LL;
		long long Y2 = (B - 1LL) * inv[A + B + C - i - 1] % mod;
		long long Y3 = ncr(B + C - 1, B - 1) * ncr(A + B + C - i - 1, A - i) % mod;
		long long YY = (Y1 * Y2 % mod) * Y3 % mod;
		Y += YY; Y %= mod;
		Y += power2[A + B + C - i - 1] * Y3 % mod; Y %= mod;
		TotalWays += Y3; TotalWays %= mod;
	}

	// X の合計を求める
	long long X1 = power2[A + B + C - 1] - 1LL;
	long long X2 = (A - 1LL) * inv[A + B + C - 1] % mod;
	long long X3 = TotalWays;
	long long X = 0;
	X += (X1 * X2 % mod) * X3 % mod;
	X += power2[A + B + C - 1] * X3 % mod;
	X %= mod;

	// X + Y + Z の合計を求める
	long long Total = 0;
	long long T1 = TotalWays;
	long long T2 = power2[A + B + C] - 1LL;
	Total = T1 * T2 % mod;

	// 最後に出力する
	long long Answer = (Total - X - Y + mod * 2LL) % mod;
	cout << Answer << endl;
	return 0;
}