Buggy python submission (verdict: Time Limit Exceeded):
from itertools import combinations
import sys

N = int(input())
XY = [list(map(int, input().split())) for _ in range(N)]

min_diff = 10**9
max_diff = 1
min_sum = 2 * 10**9
max_sum = 2

for x,y in XY:
    min_diff = min(x-y, min_diff)
    max_diff = max(x-y, max_diff)
    min_sum = min(x+y, min_sum)
    max_sum = max(x+y, max_sum)

cand_set = set()
for x,y in XY:
    if x-y in (min_diff, max_diff) or x+y in (min_sum, max_sum):
        cand_set.add((x, y))

if len(cand_set) == N:
    print(max(max_sum-min_sum, max_diff - min_diff))
    sys.exit()

dist = 0
for p1, p2 in combinations(cand_set, 2):
    dist = max(dist, abs(p1[0]-p2[0]) + abs(p1[1]-p2[1]))
    
print(dist)

Fixed submission:
N = int(input())
XY = [list(map(int, input().split())) for _ in range(N)]

min_diff = 10**9
max_diff = -10**9
min_sum = 2 * 10**9
max_sum = 2

for x,y in XY:
    min_diff = min(x-y, min_diff)
    max_diff = max(x-y, max_diff)
    min_sum = min(x+y, min_sum)
    max_sum = max(x+y, max_sum)

print(max(max_sum-min_sum, max_diff-min_diff))

Buggy python submission (verdict: Runtime Error):
from itertools import combinations
import sys

N = int(input())
XY = [list(map(int, input().split())) for _ in range(N)]

min_diff = 10**9
max_diff = 1
min_sum = 2 * 10**9
max_sum = 2

for x,y in XY:
    min_diff = min(x-y, min_diff)
    max_diff = max(x-y, max_diff)
    min_sum = min(x+y, min_sum)
    max_sum = max(x+y, max_sum)

cand_set = set()
for x,y in XY:
    if x-y in (min_diff, max_diff) or x+y in (min_sum, max_sum):
        cand_set.add((x, y))

if len(cand_set) == N:
    print(max(max_sum-min_sum, mad_diff - min_diff))
    sys.exit()

dist = 0
for p1, p2 in combinations(cand_set, 2):
    dist = max(dist, abs(p1[0]-p2[0]) + abs(p1[1]-p2[1]))
    
print(dist)

Fixed submission:
N = int(input())
XY = [list(map(int, input().split())) for _ in range(N)]

min_diff = 10**9
max_diff = -10**9
min_sum = 2 * 10**9
max_sum = 2

for x,y in XY:
    min_diff = min(x-y, min_diff)
    max_diff = max(x-y, max_diff)
    min_sum = min(x+y, min_sum)
    max_sum = max(x+y, max_sum)

print(max(max_sum-min_sum, max_diff-min_diff))

Buggy python submission (verdict: Time Limit Exceeded):
from itertools import combinations

N = int(input())
XY = [list(map(int, input().split())) for _ in range(N)]

min_diff = 10**9
max_diff = 1
min_sum = 2 * 10**9
max_sum = 2

for x,y in XY:
    min_diff = min(x-y, min_diff)
    max_diff = max(x-y, max_diff)
    min_sum = min(x+y, min_sum)
    max_sum = max(x+y, max_sum)

cand_set = set()
for x,y in XY:
    if x-y in (min_diff, max_diff) or x+y in (min_sum, max_sum):
        cand_set.add((x, y))

dist = 0
for p1, p2 in combinations(cand_set, 2):
    dist = max(dist, abs(p1[0]-p2[0]) + abs(p1[1]-p2[1]))
    
print(dist)

Fixed submission:
N = int(input())
XY = [list(map(int, input().split())) for _ in range(N)]

min_diff = 10**9
max_diff = -10**9
min_sum = 2 * 10**9
max_sum = 2

for x,y in XY:
    min_diff = min(x-y, min_diff)
    max_diff = max(x-y, max_diff)
    min_sum = min(x+y, min_sum)
    max_sum = max(x+y, max_sum)

print(max(max_sum-min_sum, max_diff-min_diff))

Buggy python submission (verdict: Runtime Error):
from itertools import combinations

N = int(input())
XY = [list(map(int, input().split())) for _ in range(N)]

min_diff = 10**9
max_diff = 1
min_sum = 2 * 10**9
max_sum = 2

for x,y in XY:
    min_diff = min(x-y, min_x)
    max_diff = max(x-y, max_x)
    min_sum = min(x+y, min_sum)
    max_sum = max(x+y, max_sum)

cand_set = set()
for x,y in XY:
    if x-y in (min_diff, max_diff) or x+y in (min_sum, max_sum):
        cand_set.add((x, y))

dist = 0
for p1, p2 in combinations(cand_set, 2):
    print(p1, p2)
    dist = max(dist, abs(p1[0]-p2[0]) + abs(p1[1]-p2[1]))
    
print(dist)

Fixed submission:
N = int(input())
XY = [list(map(int, input().split())) for _ in range(N)]

min_diff = 10**9
max_diff = -10**9
min_sum = 2 * 10**9
max_sum = 2

for x,y in XY:
    min_diff = min(x-y, min_diff)
    max_diff = max(x-y, max_diff)
    min_sum = min(x+y, min_sum)
    max_sum = max(x+y, max_sum)

print(max(max_sum-min_sum, max_diff-min_diff))