#include <iostream>
#include <atcoder/modint>
#include <vector>

using namespace std;
using namespace atcoder;
using ll = long long;
using mint = modint1000000007;
const int MX = 3000010;
mint f[MX],inv[MX],fi[MX];
constexpr ll mod = 1000000007;
void solve(){
    inv[1] = 1;
    for(int i=2;i<MX;i++){
        inv[i] = mod - (mod/i)*inv[mod%i];
    }
    f[0] = fi[0] = 1;
    for(int i=1;i<MX;i++){
        f[i] = f[i-1]*i;
        fi[i] = fi[i-1]*inv[i];
    }
}

mint nck(ll n, ll k){
    if(n<0 || k<0 || n<k) return 0;
    return f[n]*fi[k]*fi[n-k];
}

mint pw(mint a,ll x){
    mint ret = 1;
    while(x){
        if(x&1) (ret *= a);
        (a *= a); x /= 2;
    }
    return ret;
}

int main(){
    int i,x,y,z; cin >> x >> y >> z;
    int m = x + y + z;
    if(m==0){
        cout << 1 << "\n";
        return 0;
    }
    solve();
    vector<mint> f(m + 1);
    for(i=0;i<=m;i++){
        f[i] = (m + 1 - i)&1 ? -nck(m + 1,i) : nck(m + 1,i);
    }
    for(i=0;i<=m;i++) f[i] *= -1;
    f[0]++;
    for(i=0;i<=m;i++) f[i] *= inv[2];
    for(i=1;i<=m;i++) f[i] += f[i - 1]*inv[2];
    // for(i=0;i<=m;i++) cout << f[i].val() << " ";
    // cout << "\n";
    mint ans = 0;
    for(i=1;i<=m;i++){
        ans += nck(i - 1 + x,x)*nck(i - 1 + y,y)*nck(i - 1 + z,z)*f[i];
    }
    cout << ans.val() << "\n";
}