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 Python (3.4.3) (judge verdict: Accepted)

from collections import Counter
N, C = list(map(int, input().split()))
D = [list(map(int, input().split())) for _ in range(C)]
c = [list(map(int, input().split())) for _ in range(N)]
'''
D0 = {}
D1 = {}
D2 = {}
for color in range(1, C + 1):
    D0[color] = 0
    D1[color] = 0
    D2[color] = 0
    
for color in range(1, C + 1):
    for i in range(N):
        for j in range(N):
            if (i + j) % 3 == 0:
                D0[color] = D0[color] + D[ c[i][j] - 1 ][ color - 1 ] 
            if (i + j) % 3 == 1:
                D1[color] = D1[color] + D[ c[i][j] - 1 ][ color - 1 ] 
            if (i + j) % 3 == 2:
                D2[color] = D2[color] + D[ c[i][j] - 1 ][ color - 1 ] 

ans = 1000000000000000
for i in range(1, C + 1):
    for j in range(1, C + 1):
        for k in range(1, C + 1):
            if i != j and j != k and k != i:
                tmp = D0[i] + D1[j] + D2[k]
                if tmp < ans:
                    ans = tmp
print(ans)
'''
diclist = [Counter() for _ in range(3)]
for i in range(N):
    for j in range(N):
        diclist[(i+j)%3][c[i][j]] += 1

ans = 100000000000000
for i in range(C):
    for j in range(C):
        for k in range(C):
            tmp = 0
            if i != j and j != k and k != i:
                for l, v in diclist[0].items():
                    tmp += D[l - 1][i] * v
                for l, v in diclist[1].items():
                    tmp += D[l - 1][j] * v
                for l, v in diclist[2].items():
                    tmp += D[l - 1][k] * v
                if tmp < ans:
                    ans = tmp
print(ans)