Buggy python submission (verdict: Runtime Error):
import fractions
from functools import reduce

n = int(input())

# a = list(map(int,input().split()))

a = [4,8,12,9,16]


def gcd_list(numbers):
    return reduce(fractions.gcd, numbers)


gcd_l = [a[0]]
gcd_r = [a[-1]]
for i in range(1,n):
    gcd_l.append(fractions.gcd(gcd_l[i-1],a[i]))
    gcd_r.append(fractions.gcd(gcd_r[i-1],a[-i-1]))

gcd_r.reverse()

ans = max(gcd_l[1],gcd_r[-2])
for i in range(1,n-1):
    gcd = fractions.gcd(gcd_l[i-1],gcd_r[i+1])
    ans = max(ans,gcd)

print(ans)

Fixed submission:
import fractions
from functools import reduce

n = int(input())

a = list(map(int,input().split()))
#
# a = [4,8,12,9,16]


def gcd_list(numbers):
    return reduce(fractions.gcd, numbers)


gcd_l = [a[0]]
gcd_r = [a[-1]]
for i in range(1,n):
    gcd_l.append(fractions.gcd(gcd_l[i-1],a[i]))
    gcd_r.append(fractions.gcd(gcd_r[i-1],a[-i-1]))

gcd_r.reverse()

ans = max(gcd_r[1],gcd_l[-2])
for i in range(1,n-1):
    gcd = fractions.gcd(gcd_l[i-1],gcd_r[i+1])
    ans = max(ans,gcd)

print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import fractions
from functools import reduce

n = int(input())

a = list(map(int,input().split()))


def gcd_list(numbers):
    return reduce(fractions.gcd, numbers)


gcd_l = [0]
gcd_r = []
for i in range(1,n+1):
    a_l = a[:i-1]
    a_r = a[i:]
    if a_l:
        gcd_l.append(gcd_list(a_l))
    if a_r:
        gcd_r.append(gcd_list(a_r))
gcd_r = gcd_r + [0]

ans = 0
for i in range(n):
    if gcd_l[i] == 0:
        gcd = gcd_r[i]
    if gcd_r[i] == 0:
        gcd = gcd_l[i]
    else:
        gcd = fractions.gcd(gcd_l[i],gcd_r[i])
    ans = max(gcd,ans)

print(ans)

Fixed submission:
import fractions
from functools import reduce

n = int(input())

a = list(map(int,input().split()))
#
# a = [4,8,12,9,16]


def gcd_list(numbers):
    return reduce(fractions.gcd, numbers)


gcd_l = [a[0]]
gcd_r = [a[-1]]
for i in range(1,n):
    gcd_l.append(fractions.gcd(gcd_l[i-1],a[i]))
    gcd_r.append(fractions.gcd(gcd_r[i-1],a[-i-1]))

gcd_r.reverse()

ans = max(gcd_r[1],gcd_l[-2])
for i in range(1,n-1):
    gcd = fractions.gcd(gcd_l[i-1],gcd_r[i+1])
    ans = max(ans,gcd)

print(ans)

Buggy python submission (verdict: Runtime Error):
import math
from functools import reduce
from random import randint
import time

n = int(input())

a = list(map(int,input().split()))


def gcd_list(numbers):
    return reduce(math.gcd, numbers)


gcd_l = [0]
gcd_r = []
for i in range(1,n+1):
    a_l = a[:i-1]
    a_r = a[i:]
    if a_l:
        gcd_l.append(gcd_list(a_l))
    if a_r:
        gcd_r.append(gcd_list(a_r))
gcd_r = gcd_r + [0]

ans = 0
for i in range(n):
    if gcd_l[i] == 0:
        gcd = gcd_r[i]
    if gcd_r[i] == 0:
        gcd = gcd_l[i]
    else:
        gcd = math.gcd(gcd_l[i],gcd_r[i])
    ans = max(gcd,ans)

print(ans)

Fixed submission:
import fractions
from functools import reduce

n = int(input())

a = list(map(int,input().split()))
#
# a = [4,8,12,9,16]


def gcd_list(numbers):
    return reduce(fractions.gcd, numbers)


gcd_l = [a[0]]
gcd_r = [a[-1]]
for i in range(1,n):
    gcd_l.append(fractions.gcd(gcd_l[i-1],a[i]))
    gcd_r.append(fractions.gcd(gcd_r[i-1],a[-i-1]))

gcd_r.reverse()

ans = max(gcd_r[1],gcd_l[-2])
for i in range(1,n-1):
    gcd = fractions.gcd(gcd_l[i-1],gcd_r[i+1])
    ans = max(ans,gcd)

print(ans)