Buggy python submission (verdict: Runtime Error):
#!/usr/bin/env python3
import sys
import fractions
import math


def solve(N: int, A: "List[int]"):
    L = []
    last = A[0]
    for i in range(N):
        last = math.gcd(last, A[i])
        L.append(last)
    last = A[-1]
    R = []
    for i in range(1, N+1):
        last = math.gcd(last, A[-i])
        R.append(last)
    R.reverse()
    if N == 2:
        print(max(A[0], A[1]))
        return
    maxGCD = max(L[-2], R[-2])
    for i in range(1, N-1):
        maxGCD = max(math.gcd(L[i-1], R[i+1]), maxGCD)
    print(maxGCD)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    solve(N, A)


if __name__ == '__main__':
    main()


Fixed submission:
#!/usr/bin/env python3
import sys
import fractions
import math


def solve(N: int, A: "List[int]"):
    L = []
    last = A[0]
    for i in range(N):
        last = fractions.gcd(last, A[i])
        L.append(last)
    last = A[-1]
    R = []
    for i in range(1, N+1):
        last = fractions.gcd(last, A[-i])
        R.append(last)
    R.reverse()
    if N == 2:
        print(max(A[0], A[1]))
        return
    maxGCD = max(L[-2], R[1])
    for i in range(1, N-1):
        maxGCD = max(fractions.gcd(L[i-1], R[i+1]), maxGCD)
    print(maxGCD)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    solve(N, A)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
#!/usr/bin/env python3
import sys
import fractions
import math


def solve(N: int, A: "List[int]"):
    L = []
    last = A[0]
    for i in range(N):
        last = math.gcd(last, A[i])
        L.append(last)
    last = A[-1]
    R = []
    for i in range(1, N+1):
        last = math.gcd(last, A[-i])
        R.append(last)
    R.reverse()
    maxGCD = max(L[-2], R[-2])
    for i in range(1, N-1):
        maxGCD = max(math.gcd(L[i-1], R[i+1]), maxGCD)
    print(maxGCD)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    solve(N, A)


if __name__ == '__main__':
    main()


Fixed submission:
#!/usr/bin/env python3
import sys
import fractions
import math


def solve(N: int, A: "List[int]"):
    L = []
    last = A[0]
    for i in range(N):
        last = fractions.gcd(last, A[i])
        L.append(last)
    last = A[-1]
    R = []
    for i in range(1, N+1):
        last = fractions.gcd(last, A[-i])
        R.append(last)
    R.reverse()
    if N == 2:
        print(max(A[0], A[1]))
        return
    maxGCD = max(L[-2], R[1])
    for i in range(1, N-1):
        maxGCD = max(fractions.gcd(L[i-1], R[i+1]), maxGCD)
    print(maxGCD)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    solve(N, A)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
#!/usr/bin/env python3
import sys
import math


def solve(N: int, A: "List[int]"):
    L = []
    last = A[0]
    for i in range(N):
        last = math.gcd(last, A[i])
        L.append(last)
    last = A[-1]
    R = []
    for i in range(1, N+1):
        last = math.gcd(last, A[-i])
        R.append(last)
    maxGCD = max(L[-2], R[-2])
    for i in range(0, N-1):
        maxGCD = max(math.gcd(L[i], R[i]), maxGCD)
    print(maxGCD)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    solve(N, A)


if __name__ == '__main__':
    main()


Fixed submission:
#!/usr/bin/env python3
import sys
import fractions
import math


def solve(N: int, A: "List[int]"):
    L = []
    last = A[0]
    for i in range(N):
        last = fractions.gcd(last, A[i])
        L.append(last)
    last = A[-1]
    R = []
    for i in range(1, N+1):
        last = fractions.gcd(last, A[-i])
        R.append(last)
    R.reverse()
    if N == 2:
        print(max(A[0], A[1]))
        return
    maxGCD = max(L[-2], R[1])
    for i in range(1, N-1):
        maxGCD = max(fractions.gcd(L[i-1], R[i+1]), maxGCD)
    print(maxGCD)
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    A = [int(next(tokens)) for _ in range(N)]  # type: "List[int]"
    solve(N, A)


if __name__ == '__main__':
    main()