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use std::iter;

fn main() {
    let mut lines = std::io::stdin().lines().map(|x| x.unwrap());
    let (m, mut k) = {
        let nmk = lines
            .next()
            .unwrap()
            .split_whitespace()
            .map(|x| str::parse(x).unwrap())
            .collect::<Vec<usize>>();
        (nmk[1], nmk[2])
    };
    let a = lines
        .map(|l| {
            l.split_whitespace()
                .map(|x| str::parse(x).unwrap())
                .collect()
        })
        .collect::<Vec<Vec<i64>>>();
    let mut decreasing = vec![];
    let mut increasing = vec![];
    for mut f in a {
        if f.first() < f.last() {
            increasing.push(f);
        } else {
            decreasing.append(&mut f);
        }
    }
    decreasing.sort_by(|a, b| b.cmp(a));
    let decreasing_prefix = add_prefix(&decreasing);
    let mut increasing = increasing
        .into_iter()
        .map(|x| (add_prefix(&x), x))
        .collect::<Vec<_>>();
    increasing.sort_by(|(a, _), (b, _)| b.last().unwrap().cmp(a.last().unwrap()));

    // eprintln!("{:?} {:?}", (&decreasing_prefix, &decreasing), increasing);
    let mut decreasing_usage = decreasing.len().min(k);
    let mut increasing_usage = 0;
    let mut score = decreasing_prefix[decreasing_usage] /* - decreasing_prefix[0] */;
    k -= decreasing_usage;
    // eprintln!("{} {} {} {}", score, increasing_usage, decreasing_usage, k);
    while increasing_usage < increasing.len() {
        if k >= m {
            score += increasing[increasing_usage].0.last().unwrap();
            increasing_usage += 1;
            k -= m;
        } else {
            let sub = m - k;
            if decreasing_usage < sub {
                break;
            }
            let decreasing_sub =
                decreasing_prefix[decreasing_usage] - decreasing_prefix[decreasing_usage - sub];
            let increasing_add = *increasing[increasing_usage].0.last().unwrap();
            if increasing_add < decreasing_sub {
                break;
            }
            decreasing_usage -= sub;
            increasing_usage += 1;
            k = 0;
            score += increasing_add - decreasing_sub;
        }
    }
    // eprintln!("{} {} {} {}", score, increasing_usage, decreasing_usage, k);

    let add_decreasing = k.min(decreasing_usage - decreasing.len());
    if add_decreasing > 0 {
        panic!()
    }
    // eprintln!("add_decreasing {}", add_decreasing);
    // score +=
    //     decreasing_prefix[decreasing_usage + add_decreasing] - decreasing_prefix[decreasing_usage];
    // decreasing_usage += add_decreasing;
    // k -= add_decreasing;
    // eprintln!("{} {} {} {}", score, increasing_usage, decreasing_usage, k);

    let init_score = score;

    let max_sub = (m - 1).min(decreasing.len() - decreasing_usage);
    for i in &increasing[0..increasing_usage] {
        for sub in 1..=max_sub {
            // eprintln!("sub {} {:?}", sub, i);
            let decreasing_add =
                decreasing_prefix[decreasing_usage + sub] - decreasing_prefix[decreasing_usage];
            let increasing_sub = i.0[m] - i.0[m - sub];
            let this_score = init_score + decreasing_add - increasing_sub;
            score = score.max(this_score);
            // eprintln!("{}", this_score);
        }
    }

    let min_sub = (m - k).saturating_sub(decreasing_usage).max(1);
    let max_sub = (m - k).min(m - 1);
    if increasing_usage < increasing.len() {
        for i in 0..increasing_usage {
            for sub in min_sub..=max_sub {
                // eprintln!("sub2 {} {:?}", sub, increasing[i]);
                let increasing_add = increasing[increasing_usage].0.last().unwrap();
                let increasing_sub = increasing[i].0[m] - increasing[i].0[m - sub];
                let decreasing_sub = decreasing_prefix[decreasing_usage]
                    - decreasing_prefix[decreasing_usage - (m - sub - k)];
                let this_score = init_score + increasing_add - increasing_sub - decreasing_sub;
                score = score.max(this_score);
                // eprintln!("{}", this_score);
            }
        }
    }

    let max_add = (m - 1).min(decreasing_usage + k);
    for i in increasing_usage..increasing.len() {
        for add in k..=max_add {
            // eprintln!("add {} {:?}", add, increasing[i]);
            let decreasing_sub = decreasing_prefix[decreasing_usage]
                - decreasing_prefix[decreasing_usage - (add - k)];
            let increasing_add = increasing[i].0[add];
            let mut this_score = init_score + increasing_add - decreasing_sub;
            // eprintln!("{}", this_score);
            let mut this_decreasing_usage = decreasing_usage - (add - k);
            for j in (0..increasing_usage).rev() {
                // eprintln!("add2 {:?}", increasing[j]);
                if this_decreasing_usage + m > decreasing.len() {
                    break;
                }
                let decreasing_add =
                    decreasing_prefix[this_decreasing_usage + m] - decreasing_prefix[this_decreasing_usage];
                let increasing_sub = increasing[j].0[m];
                // eprintln!("{} {}", decreasing_add, increasing_sub);
                if decreasing_add < increasing_sub {
                    break;
                }
                this_score += decreasing_add - increasing_sub;
                this_decreasing_usage += m;
                // eprintln!("{}", this_score);
            }
            score = score.max(this_score);
        }
    }

    println!("{}", score);
}

fn add_prefix(inp: &[i64]) -> Vec<i64> {
    iter::once(0)
        .chain(inp.iter().scan(0, |x, y| {
            *x += y;
            Some(*x)
        }))
        .collect()
}