fn main() {
    let ref mut buf = String::new();
    std::io::Read::read_to_string(&mut std::io::stdin(), buf).ok();
    let mut iter = buf.split_whitespace();

    macro_rules! scan {
        ([$t:tt; $n:expr]) => ((0..$n).map(|_| scan!($t)).collect::<Vec<_>>());
        (($($t:tt),*)) => (($(scan!($t)),*));
        (Usize1) => (scan!(usize) - 1);
        (Bytes) => (scan!(String).into_bytes());
        ($t:ty) => (iter.next().unwrap().parse::<$t>().unwrap());
    }

    let n = scan!(usize);
    let mut s = {
        (0..n)
            .map(|_| scan!(Bytes))
            .filter(|s| s.windows(2).all(|s| s[0] <= s[1]))
            .map(|s| (*s.first().unwrap(), *s.last().unwrap(), s.len()))
            .collect::<Vec<_>>()
    };
    s.sort();

    let mut dp = vec![0; 26];
    let mut p = 0;
    for (s, e, l) in s {
        let (s, e) = ((s - b'a') as usize, (e - b'a') as usize);
        while s != p {
            dp[p + 1] = dp[p + 1].max(dp[p]);
            p += 1;
        }
        dp[e] = dp[e].max(dp[s] + l);
    }

    let ans = dp.iter().max().unwrap();
    println!("{}", ans);
}