const MOD: usize = 1e9 as usize + 7;

fn power(base: usize, times: usize) -> usize {
    if times == 0 { return 1usize; }
    if times == 1 { return base; }
    let temp = power(base, times/2);
    temp * temp % MOD * power(base, times%2) % MOD
}

fn fact_inv(size: usize) -> (Vec<usize>, Vec<usize>) {
    let mut facts = vec![0usize; size+1];
    let mut fact_invs = vec![0usize; size+1];
    let mut invs = vec![0usize; size+1];
    facts[0] = 1;
    facts[1] = 1;
    fact_invs[0] = 1;
    fact_invs[1] = 1;
    invs[1] = 1;
    for i in 2..=size {
        facts[i] = facts[i-1] * i % MOD;
        invs[i] = MOD - invs[MOD % i] * (MOD / i) % MOD;
        fact_invs[i] = fact_invs[i - 1] * invs[i] % MOD;
    }
    (facts, fact_invs)
}

fn comb(n: usize, r: usize, facts: &Vec<usize>, fact_invs: &Vec<usize>) -> usize {
    facts[n] * fact_invs[r] % MOD * fact_invs[n-r] % MOD
}

fn main() {
    let mut abc = String::new();
    std::io::stdin().read_line(&mut abc).ok();
    let abc: Vec<usize> = abc.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let a = abc[0];
    let b = abc[1];
    let c = abc[2];

    let n = a+b+c;
    let (facts, fact_invs) = fact_inv(n+10);
    let mut result = 0usize;
    let mut p2sum = vec![1usize; n];
    for i in 1..n { p2sum[i] = p2sum[i-1] * 2 % MOD; }
    for i in 1..n { p2sum[i] = (p2sum[i] + p2sum[i-1]) % MOD; }
    for starta in 1..=a {
        let total_combs = comb(n-starta-1, b-1, &facts, &fact_invs)* comb(n-starta-b, c, &facts, &fact_invs) % MOD;
        let prob = c * power(n-starta-1, MOD-2) % MOD;
        result += prob * p2sum[n-starta-2] % MOD * total_combs % MOD;
        result %= MOD;
    }
    println!("{}", result);
}