Buggy python submission (verdict: Runtime Error):
import functools  # Python3 
N,M = map(int,input().split())
x, y, z = [0] * N, [0] * N, [0] * N
for i in range(N):
	x[i], y[i], z[i] = map(int,input().split())

if M==0:
	print(0)
	exit()

ppp = functools.reduce(lambda x,y: x+y,sorted([ x[i]+y[i]+z[i] for i in range(N)])[-M:])
pmp = functools.reduce(lambda x,y: x+y,sorted([ x[i]-y[i]+z[i] for i in range(N)])[-M:])
ppm = functools.reduce(lambda x,y: x+y,sorted([ x[i]+y[i]-z[i] for i in range(N)])[-M:])
pmm = functools.reduce(lambda x,y: x+y,sorted([ x[i]-y[i]-z[i] for i in range(N)])[-M:])
mpp = functools.reduce(lambda x,y: x+y,sorted([-x[i]+y[i]+z[i] for i in range(N)])[-M:])
mpm = functools.reduce(lambda x,y: x+y,sorted([-x[i]+y[i]-z[i] for i in range(N)])[-M:])
mmp = functools.reduce(lambda x,y: x+y,sorted([-x[i]-y[i]+z[i] for i in range(N)])[-M:])
mmm = functools.reduce(lambda x,y: x+y,sorted([-x[i]-y[i]-z[i] for i in range(N)])[-M:])

MAX = 0
for lis in [ppp,pmp,ppm,pmm,mpp,mpm,mmp,mmm]:
	if lis  > MAX:
		MAX = lis
print(MAX)


Fixed submission:
N,C = map(int,input().split())
D = []
for i in range(C):
    D.append(list(map(int,input().split())))
c = []
for i in range(N):
    c.append(list(map(int,input().split())))

import itertools
current_minimum = 1000 * 500 * 500 + 1
Z = []
Z.append([0]*C)
Z.append([0]*C)
Z.append([0]*C)
#print(Z)

for (i,j) in itertools.product(range(N),range(N)):
	cur_mod = ((i+1)+(j+1)) % 3
	cur_color = c[i][j]
	#print(cur_mod)
	#print(cur_color)
	Z[cur_mod][cur_color-1] += 1

current_minimum = 1000 * 500 * 500 + 1
for (c0,c1,c2) in itertools.permutations(range(C), 3):
	tmp = 0
	color = [c0,c1,c2]
	for cur_mod in range(3):
		target_color = color[cur_mod]
		for cur_color in range(C):
			tmp += Z[cur_mod][cur_color] * D[cur_color][target_color]
	if current_minimum >= tmp:
		current_minimum = tmp
print(current_minimum)

Buggy python submission (verdict: Time Limit Exceeded):
N,C = map(int,input().split())
D = []
for i in range(C):
    D.append(list(map(int,input().split())))
c = []
for i in range(N):
    c.append(list(map(int,input().split())))

current_minimum = 1000 * 500 * 500 + 1

import itertools
for (c0,c1,c2) in itertools.permutations(range(C), 3):
	color = [c0,c1,c2]
	tmp = 0
	for (i,j) in itertools.product(range(N),range(N)):
		current_color = c[i][j]
		target_color = color[((i+1)+(j+1)) % 3]
		tmp += D[current_color - 1][target_color-1]
	if current_minimum >= tmp:
		current_minimum = tmp
print(current_minimum)

Fixed submission:
N,C = map(int,input().split())
D = []
for i in range(C):
    D.append(list(map(int,input().split())))
c = []
for i in range(N):
    c.append(list(map(int,input().split())))

import itertools
current_minimum = 1000 * 500 * 500 + 1
Z = []
Z.append([0]*C)
Z.append([0]*C)
Z.append([0]*C)
#print(Z)

for (i,j) in itertools.product(range(N),range(N)):
	cur_mod = ((i+1)+(j+1)) % 3
	cur_color = c[i][j]
	#print(cur_mod)
	#print(cur_color)
	Z[cur_mod][cur_color-1] += 1

current_minimum = 1000 * 500 * 500 + 1
for (c0,c1,c2) in itertools.permutations(range(C), 3):
	tmp = 0
	color = [c0,c1,c2]
	for cur_mod in range(3):
		target_color = color[cur_mod]
		for cur_color in range(C):
			tmp += Z[cur_mod][cur_color] * D[cur_color][target_color]
	if current_minimum >= tmp:
		current_minimum = tmp
print(current_minimum)