Buggy python submission (verdict: Time Limit Exceeded):
# ABC071-C　
N = int(input())
A_list = list(map(int, input().split()))

A_set = sorted(set(A_list), reverse = True)

side_list = [0, 0]

for i in range(len(A_set)):   # 大きい順に取っていき，リストで個数を確認する
    if len(side_list) >= 4:
        break
    count = A_list.count(A_set[i])    # リストの個数を確認
    if count == 2 or count == 3:
        side_list.append(A_set[i])
    if count >= 4:
        side_list.append(A_set[i])
        side_list.append(A_set[i])
        
side_list.sort(reverse = True)
print(side_list[0] * side_list[1])

Fixed submission:
# ABC071-C
N = int(input())
A = sorted(list(map(int, input().split())), reverse = True)

for i in range(N-1):
    if A[i] == A[i+1]:
        A[i+1] = 0
    elif A[i] != A[i+1]:
        A[i] = 0
A.sort(reverse = True)
print(A[0] * A[1])

Buggy python submission (verdict: Time Limit Exceeded):
# ABC071-C　
N = int(input())
A_list = list(map(int, input().split()))

A_set = set(A_list)
A_set = sorted(A_set, reverse=True)

side_list = [0, 0]

for i in range(len(A_set)):   # 大きい順に取っていき，リストで個数を確認する
    if len(side_list) >= 4:
        break
    count = A_list.count(A_set[i])    # リストの個数を確認
    if count == 2 or count == 3:
        side_list.append(A_set[i])
    if count >= 4:
        side_list.append(A_set[i])
        side_list.append(A_set[i])
        
side_list.sort(reverse = True)
print(side_list[0] * side_list[1])

Fixed submission:
# ABC071-C
N = int(input())
A = sorted(list(map(int, input().split())), reverse = True)

for i in range(N-1):
    if A[i] == A[i+1]:
        A[i+1] = 0
    elif A[i] != A[i+1]:
        A[i] = 0
A.sort(reverse = True)
print(A[0] * A[1])

Buggy python submission (verdict: Time Limit Exceeded):
# ABC071-C　
N = int(input())
A_list = list(map(int, input().split()))

A_set = set(A_list)
A_set = sorted(A_set, reverse=True)

side_list = [0, 0]

for i in range(len(A_set)):   # 大きい順に取っていき，リストで個数を確認する
    if len(side_list) >= 4:
        break
    count = A_list.count(A_set[i])    # リストの個数を確認
    if count == 2 or count == 3:
        side_list.append(A_set[i])
    if count >= 4:
        side_list.append(A_set[i])
        side_list.append(A_set[i])
        
side_list.sort(reverse = True)
print(side_list[0] * side_list[1])

Fixed submission:
# ABC071-C
N = int(input())
A = sorted(list(map(int, input().split())), reverse = True)

for i in range(N-1):
    if A[i] == A[i+1]:
        A[i+1] = 0
    elif A[i] != A[i+1]:
        A[i] = 0
A.sort(reverse = True)
print(A[0] * A[1])

Buggy python submission (verdict: Runtime Error):
# ABC071-C
import collections
N = int(input())
A_list = sorted(list(map(int, input().split())), reverse = True)
A_set = set(A_list)
A_set = sorted(A_set, reverse=True)
ans_list = [0]   
ans_rectangle_list = []   # 長方形を作る辺を入れる
rec_counter = 0   # 大きい辺を入れる回数，二回入れば良い
for i in range(len(A_set)):   # 大きい順に取っていき，リストで個数を確認する
    if rec_counter == 2:
        break
    count = A_list.count(A_set[i])    # リストの個数を確認
    if count  == 2 or count == 3:   # 対辺を作れる時
        ans_rectangle_list.append(A_set[i])
        rec_counter += 1
    elif count >= 4:   # 4辺全てを作れる
        ans_list.append(A_set[i] ** 2)

if rec_counter == 2:
    rec_ans = ans_rectangle_list[0] * ans_rectangle_list[1]
if len(ans_list) == 0 and len(ans_rectangle_list) <= 1:
    print(0)
else:
    if max(ans_list) > rec_ans:
        print(max(ans_list))
    elif max(ans_list) <= rec_ans:
        print(rec_ans)

Fixed submission:
# ABC071-C
N = int(input())
A = sorted(list(map(int, input().split())), reverse = True)

for i in range(N-1):
    if A[i] == A[i+1]:
        A[i+1] = 0
    elif A[i] != A[i+1]:
        A[i] = 0
A.sort(reverse = True)
print(A[0] * A[1])