Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
p = set()
for _ in range(N):
    x, y = map(int, input().split())
    if (x, y) not in p:
        p.add((x, y))
p = list(p)

def cross(a, b, c, d):
    return (b[0]-a[0])*(d[1]-c[1]) - (b[1]-a[1])*(d[0]-c[0])


def convex_hull(ps):
    qs = []
    n = len(ps)
    for p in ps:
        while len(qs) > 1 and cross(qs[-1], qs[-2], qs[-1], p) >= 0:
            qs.pop()
        qs.append(p)
    t = len(qs)
    for i in range(n-2, -1, -1):
        p = ps[i]
        while len(qs) > t and cross(qs[-1], qs[-2], qs[-1], p) >= 0:
            qs.pop()
        qs.append(p)
    return qs


def dist(a, b):
    return abs(a[0] - b[0]) + abs(a[1] - b[1])


def rotating_calipers(ps):
    qs = convex_hull(ps)
    n = len(qs)
    if n == 2:
        return dist(qs[0], qs[1])
    i = j = 0
    for k in range(n):
        if qs[k] < qs[i]: i = k
        if qs[j] < qs[k]: j = k
    res = 0
    si = i; sj = j
    while i != sj or j != si:
        res = max(res, dist(qs[i], qs[j]))
        if cross(qs[i], qs[i-n+1], qs[j], qs[j-n+1]) < 0:
            i = (i + 1) % n
        else:
            j = (j + 1) % n
    return res


print(rotating_calipers(p))

Fixed submission:
N = int(input())
p = []
for _ in range(N):
    x, y = map(int, input().split())
    p.append((x, y))
p = sorted(p, key=lambda i: i[0] + i[1])
x1, y1 = p[0]
x2, y2 = p[-1]
res = abs((x1 + y1) - (x2 + y2))
p = sorted(p, key=lambda i: i[0] - i[1])
x1, y1 = p[0]
x2, y2 = p[-1]
res = max(abs((x1 - y1) - (x2 - y2)), res)
print(res)

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
p = set()
for _ in range(N):
    x, y = map(int, input().split())
    p.add((x, y))
p = list(p)

def cross(a, b, c, d):
    return (b[0]-a[0])*(d[1]-c[1]) - (b[1]-a[1])*(d[0]-c[0])
def convex_hull(ps):
    qs = []
    n = len(ps)
    for p in ps:
        while len(qs)>1 and cross(qs[-1], qs[-2], qs[-1], p) >= 0:
            qs.pop()
        qs.append(p)
    t = len(qs)
    for i in range(n-2, -1, -1):
        p = ps[i]
        while len(qs)>t and cross(qs[-1], qs[-2], qs[-1], p) >= 0:
            qs.pop()
        qs.append(p)
    return qs

def dist(a, b):
    return abs(a[0] - b[0]) + abs(a[1] - b[1])


def rotating_calipers(ps):
    qs = convex_hull(ps)
    n = len(qs)
    if n == 2:
        return dist(qs[0], qs[1])
    i = j = 0
    for k in range(n):
        if qs[k] < qs[i]: i = k
        if qs[j] < qs[k]: j = k
    res = 0
    si = i; sj = j
    while i != sj or j != si:
        res = max(res, dist(qs[i], qs[j]))
        if cross(qs[i], qs[i-n+1], qs[j], qs[j-n+1]) < 0:
            i = (i + 1) % n
        else:
            j = (j + 1) % n
    return res


print(rotating_calipers(p))


Fixed submission:
N = int(input())
p = []
for _ in range(N):
    x, y = map(int, input().split())
    p.append((x, y))
p = sorted(p, key=lambda i: i[0] + i[1])
x1, y1 = p[0]
x2, y2 = p[-1]
res = abs((x1 + y1) - (x2 + y2))
p = sorted(p, key=lambda i: i[0] - i[1])
x1, y1 = p[0]
x2, y2 = p[-1]
res = max(abs((x1 - y1) - (x2 - y2)), res)
print(res)

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
p = set()
for _ in range(N):
    x, y = map(int, input().split())
    p.add((x, y))
p = list(p)

res = 0
for x, y in p:
    p.sort(key=lambda i: abs(i[0] - x) + abs(i[1] - y))
    res = max(res, abs(x - p[-1][0]) + abs(y - p[-1][1]))
print(res)

Fixed submission:
N = int(input())
p = []
for _ in range(N):
    x, y = map(int, input().split())
    p.append((x, y))
p = sorted(p, key=lambda i: i[0] + i[1])
x1, y1 = p[0]
x2, y2 = p[-1]
res = abs((x1 + y1) - (x2 + y2))
p = sorted(p, key=lambda i: i[0] - i[1])
x1, y1 = p[0]
x2, y2 = p[-1]
res = max(abs((x1 - y1) - (x2 - y2)), res)
print(res)