// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------

fn run() {
    input! {
        n: usize,
        m: usize,
        a: [[u32; n]; n],
    }
    let mut ans = std::u32::MAX;
    for i in 0usize..(1 << n) {
        let mut sum = 0;
        let mut a = a.clone();
        for j in 0..n {
            if i >> j & 1 == 1 {
                for k in 0..n {
                    sum += a[k][j];
                    a[k][j] = 0;
                }
            }
        }
        for ld in 0..2 {
            let mut a = a.clone();
            let mut sum = sum;
            if ld == 1 {
                for i in 0..n {
                    sum += a[i][i];
                    a[i][i] = 0;
                }
            }
            for rd in 0..2 {
                let mut a = a.clone();
                let mut sum = sum;
                if rd == 1 {
                    for i in 0..n {
                        sum += a[i][n - 1 - i];
                        a[i][n - 1 - i] = 0;
                    }
                }
                let mut b = a.iter().map(|a| a.iter().sum::<u32>()).collect::<Vec<_>>();
                b.sort();
                let mut cnt = i.count_ones() as usize + ld + rd;
                let mut x = 0;
                while x < n && cnt < m {
                    sum += b[x];
                    x += 1;
                    cnt += 1;
                }
                if cnt >= m {
                    ans = ans.min(sum);
                }
            }
        }
    }
    println!("{}", ans);
}

fn main() {
    run();
}