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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const ll Inf = 9000000000000000000ll;
const int Maxn = 505;
const int Maxc = 50;

int n, c;
int D[Maxc][Maxc];
int C[Maxn][Maxn];
ll cost[3][Maxc];
ll res = Inf;

int main()
{
	scanf("%d %d", &n, &c);
	for (int i = 1; i <= c; i++)
		for (int j = 1; j <= c; j++)
			scanf("%d", &D[i][j]);
	for (int i = 1; i <= n; i++)
		for (int j = 1; j <= n; j++)
			scanf("%d", &C[i][j]);
	for (int i = 0; i < 3; i++)
		for (int j = 1; j <= c; j++) {
			cost[i][j] = 0;
			for (int r = 1; r <= n; r++)
				for (int r2 = 1; r2 <= n; r2++) if ((r + r2) % 3 == i)
					cost[i][j] += D[C[r][r2]][j];
		}
	for (int c1 = 1; c1 <= c; c1++)
		for (int c2 = 1; c2 <= c; c2++) if (c1 != c2)
			for (int c3 = 1; c3 <= c; c3++) if (c1 != c3 && c2 != c3)
				res = min(res, cost[0][c1] + cost[1][c2] + cost[2][c3]);
	cout << res << endl;
	return 0;
}