#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)
using Graph = vector<vector<ll>>;

vector<ll> fact, factinv, inv;
ll mod = 1e9 + 7;
void prenCkModp(ll n) {
	fact.resize(n + 5);
	factinv.resize(n + 5);
	inv.resize(n + 5);
	fact.at(0) = fact.at(1) = 1;
	factinv.at(0) = factinv.at(1) = 1;
	inv.at(1) = 1;
	for (ll i = 2; i < n + 5; i++) {
		fact.at(i) = (fact.at(i - 1) * i) % mod;
		inv.at(i) = mod - (inv.at(mod % i) * (mod / i)) % mod;
		factinv.at(i) = (factinv.at(i - 1) * inv.at(i)) % mod;
	}

}
ll nCk(ll n, ll k) {
	if (n < k) return 0;
	return fact.at(n) * (factinv.at(k) * factinv.at(n - k) % mod) % mod;
}

int main() {
    ll A,B,C,an=0;
    cin>>A>>B>>C;
    prenCkModp(A+B+C);
    vll T(A+B+C+3,1);
    rep(i,A+B+C+1){
        T[i+1]=(T[i]*2)%mod;
    }
    rep(i,A){
        ll p=T[A+B+C-i-2]-1;
        p*=nCk(A+B+C-i-3,C-1);
        p%=mod;
        p*=nCk(A+B-i-2,B-1);
        p%=mod;
        an+=p;
        an%=mod;
        an+=mod;
        an%=mod;
    }
    cout<<an<<endl;
}