#[allow(dead_code)]
const MOD: usize = 1_000000000 + 7;

fn main() {
    let mut cin = Scanner::new();
    let n = cin.next_usize() - 1;
    let m = cin.next_usize();
    let a = (0..m).map(|_| (0..m).map(|_| { cin.next_usize() }).collect::<Vec<_>>()).collect::<Vec<_>>();
    let max = m+1;
    let mut dp = vec![vec![vec![0; m]; m]; max];
    for k in 1..max {
        for i in 0..m {
            for j in 0..m {
                for l in 0..m {
                    dp[k][i][j] = if k == 1 {
                        std::cmp::max(dp[k][i][j], a[i][j])
                    } else {
                        std::cmp::max(dp[k][i][j], dp[k-1][i][l] + a[l][j])
                    }
                }
            }
        }
    }
    let mut max1 = vec![vec![0; m]; max];
    let mut max2 = vec![vec![0; m]; max];
    for k in 1..max {
        for i in 0..m {
            for j in 0..m {
                max1[k][i] = std::cmp::max(max1[k][i], dp[k][i][j]);
                max2[k][i] = std::cmp::max(max2[k][i], dp[k][j][i]);
            }
        }
    }
    let mut ans = 0;
    for i in 0..m {
        for a in 0..m {
            for b in 0..m {
                for k in 1..max {
                    if a+b <= n && (n-a-b)%k == 0 {
                        let q = (n-a-b)/k;
                        let val = max2[a][i] + dp[k][i][i]*q + max1[b][i];
                        ans = std::cmp::max(ans, val);
                    }
                }
            }
        }
    }
    println!("{}", ans);
}


struct Scanner {
    reader: std::io::Stdin,
    tokens: std::collections::VecDeque<String>,
}

impl Scanner {
    fn new() -> Self {
        Scanner {
            reader: std::io::stdin(),
            tokens: std::collections::VecDeque::new(),
        }
    }

    fn next(&mut self) -> String {
        if self.tokens.is_empty() {
            let mut s = String::new();
            loop {
                self.reader.read_line(&mut s).ok();
                let s = s.trim();
                if s.len() != 0 {
                    for it in s.split_whitespace() {
                        self.tokens.push_back(it.into())
                    }
                    break;
                }
            }
        }
        self.tokens.pop_front().unwrap()
    }

    fn next_generics<T>(&mut self) -> T where
        T: std::str::FromStr + std::marker::Copy,
        <T as std::str::FromStr>::Err: std::fmt::Debug
    {
        self.next().parse().unwrap()
    }
    
    #[allow(dead_code)] fn next_i32(&mut self) -> i32 { self.next_generics::<i32>() }
    #[allow(dead_code)] fn next_i64(&mut self) -> i64 { self.next_generics::<i64>() }
    #[allow(dead_code)] fn next_u64(&mut self) -> u64 { self.next_generics::<u64>() }
    #[allow(dead_code)] fn next_usize(&mut self) -> usize { self.next_generics::<usize>() }
    #[allow(dead_code)] fn next_isize(&mut self) -> isize { self.next_generics::<isize>() }
}