#include<iostream>
#include<vector>
using namespace std;

typedef long long ll;
const ll mod = 1e9 + 7;

ll modpow(ll a, ll b, ll p = 1e9+7){
    if(b == 0)  return 1;

    if(b % 2 == 0){
        ll d = modpow(a, b/2, p);
        return (d*d) % p;
    }else{
        return (a%p * modpow(a, b-1, p)) % p;
    }
}

ll po[300001], inv[300001];
void init(ll N){
    po[0] = 1;
    for(int i = 1; i < N; i++)  po[i] = (po[i-1] * i) % mod;
    inv[N-1] = modpow(po[N-1], mod-2, mod);
    for(int i = N-2; i >= 0; i--)   inv[i] = (inv[i+1] * (i+1)) % mod;
}

ll nCk(ll n, ll k){
    if(k == 0)  return 1;
    if(n < k)   return 0;
    return (((po[n]*inv[n-k])%mod)*inv[k])%mod;
}

ll nPk(ll n, ll k){
    if(k == 0)  return 1;
    if(n < k)   return 0;
    return (po[n]*inv[n-k])%mod;
}

ll nHk(ll n, ll k){
    if(n == 0 && k == 0)    return 1;
    return nCk(n+k-1, k-1);
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll a, b, c;
    cin >> a >> b >> c;
    init(a+b+c+1);
    ll ans = 0, beki = (modpow(2,a+b+c-1)-1+mod)%mod, twoinv = modpow(2, mod-2);
    for(ll i = 1; i <= a; i++){
        beki = (beki-1+mod)*twoinv%mod;
        ans += nCk(a+b+c-i-2, c-1)*nCk(a+b-i-1, b-1)%mod*beki%mod;
        ans %= mod;
    }
    cout << ans << "\n";
    return 0;
}