#include <bits/stdc++.h>

using namespace std;

using ll =  long long;
using Pll = pair<ll, ll>;
using Pii = pair<int, int>;

constexpr ll MOD = 1000000007;
constexpr long double EPS = 1e-10;
constexpr int dyx[4][2] = {
    { 0, 1}, {-1, 0}, {0,-1}, {1, 0}
};
constexpr int S_MAX = 300000;

ll fact[S_MAX+1], rfact[S_MAX+1];

ll perm(ll n, ll r){
    return (fact[n] * rfact[r]) % MOD;
}

ll comb(ll n, ll r){
    return (perm(n, r) * rfact[n-r]) % MOD;
}

void init(ll n){
    fact[0] = fact[1] = 1;
    rfact[0] = rfact[1] = 1;
    for(int i=2;i<=n;++i) {
        fact[i] = (fact[i-1] * (ll)i) % MOD;
        rfact[i] = 1;
        ll k = MOD-2;
        ll a = fact[i];
        while(k > 0){
            if(k & 1){
                rfact[i] *= a;
                rfact[i] %= MOD;
            }
            a *= a;
            a %= MOD;
            k  >>= 1;
        }
    }
}

ll modpow(ll a, ll t) {
    ll ret = 1LL;
    while(t){
        if(t & 1LL){
            ret *= a;
            ret %= MOD;
        }
        a *= a;
        a %= MOD;
        t >>= 1;
    }
    return ret;
}

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    ll a, b, c;
    cin >> a >> b >> c;
    ll s = a + b + c;
    init(s);

    ll ab_patterns[s]; // 先頭 i 文字以下が a
    ab_patterns[0] = 0;
    for(int i=1;i<=a;++i) {
        ab_patterns[i] = comb(a+b-i-1, a-i);
        ab_patterns[i] %= MOD;
    }

    ll ans = 0;
    ll patterns = 0;
    for(int i=s-3;i>=0;--i) {
        if(s-i-2 <= a) patterns += (ab_patterns[s-i-2] * comb(s-min(a, s-i-2)-1-1, c-1)) % MOD;
        patterns %= MOD;
        ans += (patterns * modpow(2LL, i)) % MOD;
        // cerr << i << ": " << patterns << endl;
        ans %= MOD;
    }
    cout << ans << endl;
}