fn main() {
    let mut xyr = String::new();
    std::io::stdin().read_line(&mut xyr).ok();
    let xyr: Vec<isize> = xyr.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let x = xyr[0];
    let y = xyr[1];
    let r: f64 = xyr[2] as f64;

    println!("{}", x.abs() + y.abs() + (r * 2.0f64.sqrt()).ceil() as isize);
}