#[allow(unused_imports)]
use std::cmp::{max, min};
#[allow(unused_imports)]
use std::collections::{HashMap, HashSet};

mod util {
    use std::io::stdin;
    use std::str::FromStr;
    use std::fmt::Debug;

    #[allow(dead_code)]
    pub fn line() -> String {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.trim().to_string()
    }

    #[allow(dead_code)]
    pub fn get<T: FromStr>() -> T
    where
        <T as FromStr>::Err: Debug,
    {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.trim().parse().unwrap()
    }

    #[allow(dead_code)]
    pub fn gets<T: FromStr>() -> Vec<T>
    where
        <T as FromStr>::Err: Debug,
    {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        line.split_whitespace()
            .map(|t| t.parse().unwrap())
            .collect()
    }

    #[allow(dead_code)]
    pub fn get2<T: FromStr, U: FromStr>() -> (T, U)
    where
        <T as FromStr>::Err: Debug,
        <U as FromStr>::Err: Debug,
    {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        let mut iter = line.split_whitespace();
        (
            iter.next().unwrap().parse().unwrap(),
            iter.next().unwrap().parse().unwrap(),
        )
    }

    #[allow(dead_code)]
    pub fn get3<S: FromStr, T: FromStr, U: FromStr>() -> (S, T, U)
    where
        <S as FromStr>::Err: Debug,
        <T as FromStr>::Err: Debug,
        <U as FromStr>::Err: Debug,
    {
        let mut line: String = String::new();
        stdin().read_line(&mut line).unwrap();
        let mut iter = line.split_whitespace();
        (
            iter.next().unwrap().parse().unwrap(),
            iter.next().unwrap().parse().unwrap(),
            iter.next().unwrap().parse().unwrap(),
        )
    }
}


#[allow(unused_macros)]
macro_rules! debug {
    ($x: expr) => {
        println!("{}: {:?}", stringify!($x), $x)
    }
}

fn main() {
    let n: usize = util::get();
    let m: usize = util::get();
    let a: Vec<Vec<usize>> = (0..m).map(|_| util::gets()).collect();

    let mut dp = vec![vec![vec![0; m]; m]; 40];
    for i in 0..40 {
        for k in 0..m {
            for j in 0..m {
                if i == 0 {
                    dp[i][k][j] = a[k][j];
                } else {
                    for h in 0..m {
                        dp[i][k][j] = max(dp[i][k][j], dp[i - 1][k][h] + dp[i - 1][h][j]);
                    }
                }
            }
        }
    }

    let mut dp2 = vec![0; m];
    for i in 0..40 {
        if ((n - 1) >> i) & 1 != 1 {
            continue;
        }
        let mut next = vec![0; m];
        for k in 0..m {
            for j in 0..m {
                next[k] = max(next[k], dp2[j] + dp[i][j][k]);
            }
        }
        dp2 = next;
    }

    println!("{}", dp2.iter().cloned().max().unwrap())
}