Buggy python submission (verdict: Runtime Error):
n=int(input())
a=list(map(int,input().split()))
from collections import Counter
data=Counter(a)
two=[]
four=[]
for i,j in data.items():
    if 2<=j<=3:
        two.append(i)
    elif 4<=j:
        four.append(i)
if len(four)==0:
    four.append(0)
    four.append(0)
    four[1]=0
elif len(two)==0:
    two.append(0)
    two.append(0)
print(max(four[0]*four[0],four[0]*four[1],two[0]*two[1],two[0]*four[0]))

Fixed submission:
n=int(input())
a=list(map(int,input().split()))
from collections import Counter
data=Counter(a)
two_i=[]
four_i=[]
for i,j in data.items():
    if 4<=j:
        four_i.append(i)
    elif 2<=j:
        two_i.append(i)
two_i.sort()
four_i.sort()
two_i.reverse()
four_i.reverse()
if len(four_i)==0:
    four_i.append(0)
if len(two_i)<=1:
    two_i.append(0)
    two_i.append(0)
four_area=four_i[0]*four_i[0]
two_area=two_i[0]*two_i[1]
mix_area=two_i[0]*four_i[0]
print(max(four_area,two_area,mix_area))

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
a=list(map(int,input().split()))
set_a=list(set(a))
a_4=[]
for i in set_a:
    if a.count(i)==1:
        a.remove(i)
    if 4<=a.count(i):
        a_4.append(i)
        a.remove(i)
if len(a)==0:
    print(0)
    exit()
a=list(set(a))
a.sort()
a.reverse()
a_4.sort()
a_4.reverse()
v=0
x=0
z=0
if 1<=len(a_4):
    v=a_4[0]*a_4[0]
if 1<=len(a):
    x=a[0]*a[1]
if 1<=len(a) and 1<=len(a_4):
    z=a[0]*a_4[0]
print(max(v,x,z))


Fixed submission:
n=int(input())
a=list(map(int,input().split()))
from collections import Counter
data=Counter(a)
two_i=[]
four_i=[]
for i,j in data.items():
    if 4<=j:
        four_i.append(i)
    elif 2<=j:
        two_i.append(i)
two_i.sort()
four_i.sort()
two_i.reverse()
four_i.reverse()
if len(four_i)==0:
    four_i.append(0)
if len(two_i)<=1:
    two_i.append(0)
    two_i.append(0)
four_area=four_i[0]*four_i[0]
two_area=two_i[0]*two_i[1]
mix_area=two_i[0]*four_i[0]
print(max(four_area,two_area,mix_area))

Buggy python submission (verdict: Runtime Error):
def test():
    n=int(input())
    a=list(map(int,input().split()))
    a.sort()
    a.reverse()
    s=list(set(a))
    s.sort()
    s.reverse()
    ans=[]
    v=0
    for i in s:
        if 4<=a.count(i):
            return i*i
        elif 2<=a.count(i)<=3:
            ans.append(i)
            return ans[0]*ans[1]
    return 0
t=test()
print(t)

Fixed submission:
n=int(input())
a=list(map(int,input().split()))
from collections import Counter
data=Counter(a)
two_i=[]
four_i=[]
for i,j in data.items():
    if 4<=j:
        four_i.append(i)
    elif 2<=j:
        two_i.append(i)
two_i.sort()
four_i.sort()
two_i.reverse()
four_i.reverse()
if len(four_i)==0:
    four_i.append(0)
if len(two_i)<=1:
    two_i.append(0)
    two_i.append(0)
four_area=four_i[0]*four_i[0]
two_area=two_i[0]*two_i[1]
mix_area=two_i[0]*four_i[0]
print(max(four_area,two_area,mix_area))

Buggy python submission (verdict: Runtime Error):
def test():
    n=int(input())
    a=list(map(int,input().split()))
    a.sort()
    a.reverse()
    s=list(set(a))
    s.sort()
    s.reverse()
    ans=[]
    v=0
    for i in s:
        if 4<=a.count(i):
            v="i"
        elif 2<=a.count(i)<=3:
            ans.append(i)
        if v or 2<=len(ans):
            return max(int(v)*int(v),ans[0]*ans[1])
    return 0
t=test()
print(t)

Fixed submission:
n=int(input())
a=list(map(int,input().split()))
from collections import Counter
data=Counter(a)
two_i=[]
four_i=[]
for i,j in data.items():
    if 4<=j:
        four_i.append(i)
    elif 2<=j:
        two_i.append(i)
two_i.sort()
four_i.sort()
two_i.reverse()
four_i.reverse()
if len(four_i)==0:
    four_i.append(0)
if len(two_i)<=1:
    two_i.append(0)
    two_i.append(0)
four_area=four_i[0]*four_i[0]
two_area=two_i[0]*two_i[1]
mix_area=two_i[0]*four_i[0]
print(max(four_area,two_area,mix_area))