Problem:
Score : 400 points

Problem Statement

There is a grid with N rows and N columns of squares. Let (i,j) be the square at the i-th row from the top and the j-th column from the left.

These squares have to be painted in one of the C colors from Color 1 to Color C. Initially, (i,j) is painted in Color c_{i,j}.

We say the grid is a good grid when the following condition is met for all i,j,x,y satisfying 1 \leq i,j,x,y \leq N:

If (i+j) \% 3=(x+y) \% 3, the color of (i,j) and the color of (x,y) are the same.

If (i+j) \% 3 \neq (x+y) \% 3, the color of (i,j) and the color of (x,y) are different.

Here, X \% Y represents X modulo Y.

We will repaint zero or more squares so that the grid will be a good grid.

For a square, the wrongness when the color of the square is X before repainting and Y after repainting, is D_{X,Y}.

Find the minimum possible sum of the wrongness of all the squares.

Constraints

1 \leq N \leq 500

3 \leq C \leq 30

1 \leq D_{i,j} \leq 1000 (i \neq j),D_{i,j}=0 (i=j)

1 \leq c_{i,j} \leq C

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N C
D_{1,1} ... D_{1,C}
:
D_{C,1} ... D_{C,C}
c_{1,1} ... c_{1,N}
:
c_{N,1} ... c_{N,N}

Output

If the minimum possible sum of the wrongness of all the squares is x, print x.

Sample Input 1

2 3
0 1 1
1 0 1
1 4 0
1 2
3 3

Sample Output 1

3

Repaint (1,1) to Color 2. The wrongness of (1,1) becomes D_{1,2}=1.

Repaint (1,2) to Color 3. The wrongness of (1,2) becomes D_{2,3}=1.

Repaint (2,2) to Color 1. The wrongness of (2,2) becomes D_{3,1}=1.

In this case, the sum of the wrongness of all the squares is 3.

Note that D_{i,j} \neq D_{j,i} is possible.

Sample Input 2

4 3
0 12 71
81 0 53
14 92 0
1 1 2 1
2 1 1 2
2 2 1 3
1 1 2 2

Sample Output 2

428

Solution in Rust (1.15.1) (judge verdict: Accepted)

#[test]
fn test_solve() {
    assert_eq!(solve("2 3\n0 1 1\n1 0 1\n1 4 0\n1 2\n3 3\n"), "3\n");
    assert_eq!(
        solve("4 3\n0 12 71\n81 0 53\n14 92 0\n1 1 2 1\n2 1 1 2\n2 2 1 3\n1 1 2 2\n"),
        "428\n"
    );
}

fn solve(src: &str) -> String {
    let mut sc = Scanner::from_str(src);

    let n: usize = sc.read();
    let cmx: usize = sc.read();

    let d: Vec<Vec<usize>> = (0..cmx)
        .map(|_| (0..cmx).map(|_| sc.read()).collect())
        .collect();
    let c: Vec<Vec<usize>> = (0..n)
        .map(|_| (0..n).map(|_| sc.read()).collect())
        .collect();
    let mut cnt = vec![vec![0; cmx]; 3];
    for i in 0..n {
        for j in 0..n {
            cnt[(i + j) % 3][c[i][j] - 1] += 1;
        }
    }
    let cnt = cnt;

    let mut ans = 1000 * 500 * 500;
    for i in 0..cmx {
        for j in 0..cmx {
            if i == j {
                continue;
            }
            for k in 0..cmx {
                if i == k || j == k {
                    continue;
                }
                let mut res = 0;
                for c in 0..cmx {
                    res += cnt[0][c] * d[c][i];
                }
                for c in 0..cmx {
                    res += cnt[1][c] * d[c][j];
                }
                for c in 0..cmx {
                    res += cnt[2][c] * d[c][k];
                }
                ans = std::cmp::min(ans, res);
            }
        }
    }

    format!("{}\n", ans)
}
fn main() {
    let mut buf = String::new();
    use std::io::{Read, Write};
    std::io::stdin().read_to_string(&mut buf).unwrap();
    std::io::stdout().write_all(solve(&buf).as_bytes()).unwrap();
}
struct Scanner<'a>(std::str::SplitWhitespace<'a>);
impl<'a> Scanner<'a> {
    fn from_str(src: &str) -> Scanner {
        Scanner(src.split_whitespace())
    }
    fn get(&mut self) -> &str {
        self.0.next().unwrap()
    }
    fn read<T: std::str::FromStr>(&mut self) -> T {
        self.get().parse().ok().unwrap()
    }
}