Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
A = list(map(int, input().split()))

nums = A[:]
import fractions

gcd_queue = [
    (nums[0], True),
    (nums[1], True),
    (fractions.gcd(nums[0], nums[1]), False),
]
for n in nums[2:]:
    tmp_queue = []
    for q in gcd_queue:
        if q[1] == True:
            tmp_queue.append((fractions.gcd(q[0], n), True))
        else:
            tmp_queue.append((fractions.gcd(q[0], n), False))
            tmp_queue.append((q[0], True))
    gcd_queue = tmp_queue[:]
#print(gcd_queue)

ans = 0
for q in gcd_queue:
    ans = max(ans, q[0])
print(ans)

Fixed submission:
N = int(input())
A = list(map(int, input().split()))

nums = A[:]
import fractions

gcd_queue = [
    (nums[0], True),
    (nums[1], True),
    (fractions.gcd(nums[0], nums[1]), False),
]
for n in nums[2:]:
    tmp_queue = []
    for q in gcd_queue:
        if q[1] == True:
            tmp_queue.append((fractions.gcd(q[0], n), True))
        else:
            tmp_queue.append((fractions.gcd(q[0], n), False))
            tmp_queue.append((q[0], True))
    gcd_queue = set(tmp_queue[:])

ans = 0
for q in gcd_queue:
    ans = max(ans, q[0])
print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
A = list(map(int, input().split()))

nums = A[:]
import math

gcd_queue = [
    (nums[0], True),
    (nums[1], True),
    (math.gcd(nums[0], nums[1]), False),
]
for n in nums[2:]:
    tmp_queue = []
    for q in gcd_queue:
        if q[1] == True:
            tmp_queue.append((math.gcd(q[0], n), True))
        else:
            tmp_queue.append((math.gcd(q[0], n), False))
            tmp_queue.append((q[0], True))
    gcd_queue = tmp_queue[:]
#print(gcd_queue)

ans = 0
for q in gcd_queue:
    ans = max(ans, q[0])
print(ans)

Fixed submission:
N = int(input())
A = list(map(int, input().split()))

nums = A[:]
import fractions

gcd_queue = [
    (nums[0], True),
    (nums[1], True),
    (fractions.gcd(nums[0], nums[1]), False),
]
for n in nums[2:]:
    tmp_queue = []
    for q in gcd_queue:
        if q[1] == True:
            tmp_queue.append((fractions.gcd(q[0], n), True))
        else:
            tmp_queue.append((fractions.gcd(q[0], n), False))
            tmp_queue.append((q[0], True))
    gcd_queue = set(tmp_queue[:])

ans = 0
for q in gcd_queue:
    ans = max(ans, q[0])
print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
A = list(map(int, input().split()))

nums = A[:]
import math

def cal_gcd(i, flag, ans):
    if i == len(nums):
        return ans
    ans_0 = -1
    if flag == False:
        ans_0 = cal_gcd(i+1, True, ans)
    
    if ans == 0:
        ans = nums[i]
    #print(i)
    ans = math.gcd(ans, nums[i])
    ans_1 = cal_gcd(i+1, flag, ans)
    return max(ans_0, ans_1)
    
ans = cal_gcd(0, False, 0)
print(ans)

Fixed submission:
N = int(input())
A = list(map(int, input().split()))

nums = A[:]
import fractions

gcd_queue = [
    (nums[0], True),
    (nums[1], True),
    (fractions.gcd(nums[0], nums[1]), False),
]
for n in nums[2:]:
    tmp_queue = []
    for q in gcd_queue:
        if q[1] == True:
            tmp_queue.append((fractions.gcd(q[0], n), True))
        else:
            tmp_queue.append((fractions.gcd(q[0], n), False))
            tmp_queue.append((q[0], True))
    gcd_queue = set(tmp_queue[:])

ans = 0
for q in gcd_queue:
    ans = max(ans, q[0])
print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
A = list(map(int, input().split()))

nums = A[:]
#print(nums)
import math

def cal_gcd(sub_nums):
    gcd_tmp = sub_nums[0]
    for i, v in enumerate(sub_nums):
        if i == 0:
            continue
        gcd_tmp = math.gcd(v, gcd_tmp)
        #print(gcd_tmp)
    return gcd_tmp

ans = 1
import itertools
for v in itertools.combinations(nums, len(nums) - 1):
    #print(v)
    gcd_tmp = cal_gcd(v)
    #print(gcd_tmp)
    ans = max(ans, gcd_tmp)
print(ans)

Fixed submission:
N = int(input())
A = list(map(int, input().split()))

nums = A[:]
import fractions

gcd_queue = [
    (nums[0], True),
    (nums[1], True),
    (fractions.gcd(nums[0], nums[1]), False),
]
for n in nums[2:]:
    tmp_queue = []
    for q in gcd_queue:
        if q[1] == True:
            tmp_queue.append((fractions.gcd(q[0], n), True))
        else:
            tmp_queue.append((fractions.gcd(q[0], n), False))
            tmp_queue.append((q[0], True))
    gcd_queue = set(tmp_queue[:])

ans = 0
for q in gcd_queue:
    ans = max(ans, q[0])
print(ans)