Buggy python submission (verdict: Runtime Error):
import fractions
n = int(input())
a = list(map(int, input().split()))
s = [0]
small = 10**9
c = 0
for i in range(n-1):
    s.append(fractions.gcd(a[i], a[i+1]))
    if fractions.gcd(a[i], a[i+1]) <= small:
        small = fractions.gcd(a[i], a[i+1])
        c = i+1
s.append(fractions.gcd(a[n-1], a[0]))
if fractions.gcd(a[n-1], a[0]) <= small:
    small = fractions.gcd(a[n-1], a[0])
    c = n
if c != 1 and c != n:
    if s[c-1] > s[c+1]:
        d = c+1
    else:
        d = c-1
if c == 1:
    if s[n] > s[2]:
        d = 2
    else:
        d = n
if c == n:
    if s[n-1] > s[1]:
        d = 1
    else:
        d = n-1
del s[c]
del s[d]
del s[0]
if n == 2:
    ans = max(a)
else:
    ans = min(s)
print(ans)

Fixed submission:
from fractions import gcd
n = int(input())
a = list(map(int, input().split()))
s1 = [0]*(n+1)
s2 = [0]*(n+1)
s1[0] = 0
s1[1] = a[0]
s2[0] = 0
s2[n] = a[n-1]
for i in range(2, n+1):
    s1[i] = gcd(s1[i-1], a[i-1])
    s2[n-i+1] = gcd(s2[n-i+2], a[n-i])
if s1[n-1] >= s2[2]:
    ans = s1[n-1]
else:
    ans = s2[2]
for i in range(2, n):
    b = gcd(s1[i-1], s2[i+1])
    if ans <= b:
        ans = b
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
n = int(input())
a = list(map(int, input().split()))
s = [0]
small = 10**9
c = 0
for i in range(n-1):
    s.append(math.gcd(a[i], a[i+1]))
    if math.gcd(a[i], a[i+1]) <= small:
        small = math.gcd(a[i], a[i+1])
        c = i+1
s.append(math.gcd(a[n-1], a[0]))
if math.gcd(a[n-1], a[0]) <= small:
    small = math.gcd(a[n-1], a[0])
    c = n
if c != 1 and c != n:
    if s[c-1] > s[c+1]:
        d = c+1
    else:
        d = c-1
if c == 1:
    if s[n] > s[2]:
        d = 2
    else:
        d = n
if c == n:
    if s[n-1] > s[1]:
        d = 1
    else:
        d = n-1
del s[c]
del s[d]
del s[0]
if n == 2:
    ans = max(a)
else:
    ans = min(s)
print(ans)

Fixed submission:
from fractions import gcd
n = int(input())
a = list(map(int, input().split()))
s1 = [0]*(n+1)
s2 = [0]*(n+1)
s1[0] = 0
s1[1] = a[0]
s2[0] = 0
s2[n] = a[n-1]
for i in range(2, n+1):
    s1[i] = gcd(s1[i-1], a[i-1])
    s2[n-i+1] = gcd(s2[n-i+2], a[n-i])
if s1[n-1] >= s2[2]:
    ans = s1[n-1]
else:
    ans = s2[2]
for i in range(2, n):
    b = gcd(s1[i-1], s2[i+1])
    if ans <= b:
        ans = b
print(ans)

Buggy python submission (verdict: Runtime Error):
import math
n = int(input())
a = list(map(int, input().split()))
s = [0]
small = 10**9
c = 0
for i in range(n-1):
    s.append(math.gcd(a[i], a[i+1]))
    if math.gcd(a[i], a[i+1]) <= small:
        small = math.gcd(a[i], a[i+1])
        c = i+1
s.append(math.gcd(a[n-1], a[0]))
if math.gcd(a[n-1], a[0]) <= small:
    small = math.gcd(a[n-1], a[0])
    c = n
if c != 1 and c != n:
    if s[c-1] > s[c+1]:
        d = c+1
    else:
        d = c-1
if c == 1:
    if s[n] > s[2]:
        d = 2
    else:
        d = n
if c == n:
    if s[n-1] > s[1]:
        d = 1
    else:
        d = n-1
del s[c]
del s[d]
del s[0]
if n == 2:
    ans = max(a)
else:
    ans = min(s)
print(ans)

Fixed submission:
from fractions import gcd
n = int(input())
a = list(map(int, input().split()))
s1 = [0]*(n+1)
s2 = [0]*(n+1)
s1[0] = 0
s1[1] = a[0]
s2[0] = 0
s2[n] = a[n-1]
for i in range(2, n+1):
    s1[i] = gcd(s1[i-1], a[i-1])
    s2[n-i+1] = gcd(s2[n-i+2], a[n-i])
if s1[n-1] >= s2[2]:
    ans = s1[n-1]
else:
    ans = s2[2]
for i in range(2, n):
    b = gcd(s1[i-1], s2[i+1])
    if ans <= b:
        ans = b
print(ans)