Buggy python submission (verdict: Runtime Error):
n=int(input())
l=list(map(int,input().split()))
l.sort()
lcount=[]
count=0
now=l[0]
for i in range(n):
  if now==l[i]:
    count+=1
  else:
    lcount.append([count,now])
    count=1
    now=l[i]
if count!=1:
  lcount.append([count,now])
if len(lcount)==1:
  print(n)
elif len(lcount)==2:
  l1=lcount[0][0]
  l2=lcount[1][0]
  if lcount[1][1]-lcount[0][1]==1:
    print(l1+l2)
  else:
    print(max(l1,l2))
else:
  count=0
  for i in range(1,len(lcount)-1):
    scount=0
    scount+=lcount[i][0]
    if lcount[i][1]-lcount[i-1][1]==1:
      scount+=lcount[i-1][0]
    if lcount[i][1]-lcount[i+1][1]==-1:
      scount+=lcount[i+1][0]
    if scount>count:
      count=scount
  count1=lcount[0][0]
  if lcount[1][1]-lcount[0][1]==1:
    count1+=lcount[1][0]
  count2=lcount[-1][0]
  if lcount[-2][1]-lcount[-1][1]==-1:
    count2+=lcount[-2][0]
  print(max(count,count1,count2))


Fixed submission:
n=int(input())
l=list(map(int,input().split()))
l.sort()
lcount=[]
count=0
now=l[0]
for i in range(n):
  if now==l[i]:
    count+=1
  else:
    lcount.append([count,now])
    count=1
    now=l[i]
lcount.append([count,now])
if len(lcount)==1:
  print(n)
elif len(lcount)==2:
  l1=lcount[0][0]
  l2=lcount[1][0]
  if lcount[1][1]-lcount[0][1]==1:
    print(l1+l2)
  else:
    print(max(l1,l2))
else:
  count=0
  for i in range(1,len(lcount)-1):
    scount=0
    scount+=lcount[i][0]
    if lcount[i][1]-lcount[i-1][1]==1:
      scount+=lcount[i-1][0]
    if lcount[i][1]-lcount[i+1][1]==-1:
      scount+=lcount[i+1][0]
    if scount>count:
      count=scount
  count1=lcount[0][0]
  if lcount[1][1]-lcount[0][1]==1:
    count1+=lcount[1][0]
  count2=lcount[-1][0]
  if lcount[-2][1]-lcount[-1][1]==-1:
    count2+=lcount[-2][0]
  print(max(count,count1,count2))

Buggy python submission (verdict: Runtime Error):
n=int(input())
l=list(map(int,input().split()))
l.sort()
lcount=[]
count=0
now=l[0]
for i in range(n):
  if now==l[i]:
    count+=1
  else:
    lcount.append([count,now])
    count=1
    now=l[i]
if count!=1:
  lcount.append([count,now])
count=0
for i in range(1,len(lcount)-1):
  scount=0
  scount+=lcount[i][0]
  if lcount[i][1]-lcount[i-1][1]==1:
    scount+=lcount[i-1][0]
  if lcount[i][1]-lcount[i+1][1]==-1:
    scount+=lcount[i+1][0]
  if scount>count:
    count=scount
count1=lcount[0][0]
if lcount[1][1]-lcount[0][1]==1:
  count1+=lcount[1][0]
count2=lcount[-1][0]
if lcount[-2][1]-lcount[-1][1]==-1:
  count2+=lcount[-2][0]
print(max(count,count1,count2))

Fixed submission:
n=int(input())
l=list(map(int,input().split()))
l.sort()
lcount=[]
count=0
now=l[0]
for i in range(n):
  if now==l[i]:
    count+=1
  else:
    lcount.append([count,now])
    count=1
    now=l[i]
lcount.append([count,now])
if len(lcount)==1:
  print(n)
elif len(lcount)==2:
  l1=lcount[0][0]
  l2=lcount[1][0]
  if lcount[1][1]-lcount[0][1]==1:
    print(l1+l2)
  else:
    print(max(l1,l2))
else:
  count=0
  for i in range(1,len(lcount)-1):
    scount=0
    scount+=lcount[i][0]
    if lcount[i][1]-lcount[i-1][1]==1:
      scount+=lcount[i-1][0]
    if lcount[i][1]-lcount[i+1][1]==-1:
      scount+=lcount[i+1][0]
    if scount>count:
      count=scount
  count1=lcount[0][0]
  if lcount[1][1]-lcount[0][1]==1:
    count1+=lcount[1][0]
  count2=lcount[-1][0]
  if lcount[-2][1]-lcount[-1][1]==-1:
    count2+=lcount[-2][0]
  print(max(count,count1,count2))