use proconio::input;
use std::io::{stdout,Write,BufWriter};

fn main() {
    input!{
        r:u32, g:u32, b:u32
    }

    let out: std::io::Stdout = stdout();
    let mut out: BufWriter<std::io::StdoutLock<'static>> = BufWriter::new(out.lock());
    
    let [c1, c2, c3] = {
        let mut tmp: [u32; 3] = [r,g,b];
        tmp.sort();
        tmp
    };

    let mut ans: u32;
    if (c3-c2)/2 >= c2-c1 {
        ans = (2*c1 + 2*c2 + c3 - (2*c1 + 2*c2 + c3)%5) / 5;
    } else {
        ans = (2*c1 + c2 + c3 - (2*c1 + c2 + c3)%4) / 4;
        if (c2-ans)%2==1 && (c3-ans)%2==1 {
            ans -= 1;
        }
    }
    write!(out, "{}", ans).unwrap();
}