use std::io::Read;

fn solve(balls: Vec<i8>) {
    let large = std::cmp::max(balls[0], balls[1]);
    let small = std::cmp::min(balls[0], balls[1]);
    let white = balls[2];
    let yukari = small + std::cmp::min(large - small, white) + std::cmp::max(0, white - large + small) / 2;
    println!("{}", yukari);
}

fn main() {
    let mut s = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let balls: Vec<i8> = s.trim().split('\n').next().unwrap().trim()
        .split_whitespace()
        .map(|s| s.parse::<i8>().unwrap())
        .collect();
    solve(balls);
}