#include<iostream>
#include<string>
#include<cstdio>
#include<cstring>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<deque>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<cassert>
using namespace std;

typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
typedef long double ld;
const int inf=1e9+7;
const ll INF=1LL<<60 ;
const ll mod=1e9+7 ;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<int, int> P;
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;
#define fr first
#define sc second
#define all(c) c.begin(),c.end()
#define pb push_back
#define debug(x)  cout << #x << " = " << (x) << endl;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
//#define int long long

ll comb(ll N_, ll C_) {
	const int NUM_=1400001;
	static ll fact[NUM_+1],factr[NUM_+1],inv[NUM_+1];
	if (fact[0]==0) {
		inv[1]=fact[0]=factr[0]=1;
		for (int i=2;i<=NUM_;++i) inv[i] = inv[mod % i] * (mod - mod / i) % mod;
		for (int i=1;i<=NUM_;++i) fact[i]=fact[i-1]*i%mod, factr[i]=factr[i-1]*inv[i]%mod;
	}
	if(C_<0 || C_>N_) return 0;
	return factr[C_]*fact[N_]%mod*factr[N_-C_]%mod;
}

ll mod_pow(ll x, ll n, ll m) {
    if(n == 0) return 1;
    ll res = mod_pow(x * x % m, n / 2, m);
    if(n & 1) res = res * x % m;
    return res;
}

//線形和に分解する→bitなら各桁で見ればok
void solve() {
	ll a, b, c; cin >> a >> b >> c;
    ll ans = 0;
    rep(i, a + b + c) {
        ll mask = mod_pow(2LL, i, mod);
        ll res = mask * comb(a + b + c, c - 1) % mod * comb(a + b + c, b) % mod;
        ans += res;
        ans %= mod;
    }
    cout << ans << endl;
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//cout << fixed << setprecision(10);
	//init();
	solve();
	//cout << "finish" << endl;
    return 0;
}