Buggy python submission (verdict: Runtime Error):
from heapq import heappop,heappush
n=int(input())
pair=[i for i in range(n)]
que=[]
e=[None]*n
for i in range(n):
  x,y=map(int,input().split())
  e[i]=(i,x,y)
ex=sorted(e,key=lambda x:x[1])
ey=sorted(e,key=lambda x:x[2])
for i in range(n-1):
  w=ex[i+1][1]-ex[i][1]
  heappush(que,(w,ex[i][0],ex[i+1][0]))
for i in range(n-1):
  w=ey[i+1][2]-ey[i][2]
  heappush(que,(w,ey[i][0],ey[i+1][0]))
def find(x):
  if x==pair[x]:return x
  else:
    tmp=find(pair[x])
    pair[x]=tmp
    return tmp
q=[]
ans=0
while que:
  w,s,t=heappop(que)
  root_s=find(s)
  root_t=find(t)
  if root_s!=root_t:
    pair[root_s]=root_t
    ans+=w
print(ans)

Fixed submission:
from heapq import heappop,heappush
import sys
sys.setrecursionlimit(10**6)
n=int(input())
pair=[i for i in range(n)]
que=[]
e=[None]*n
for i in range(n):
  x,y=map(int,input().split())
  e[i]=(i,x,y)
ex=sorted(e,key=lambda x:x[1])
ey=sorted(e,key=lambda x:x[2])
for i in range(n-1):
  w=ex[i+1][1]-ex[i][1]
  heappush(que,(w,ex[i][0],ex[i+1][0]))
for i in range(n-1):
  w=ey[i+1][2]-ey[i][2]
  heappush(que,(w,ey[i][0],ey[i+1][0]))
def find(x):
  if x==pair[x]:return x
  else:
    tmp=find(pair[x])
    pair[x]=tmp
    return tmp
q=[]
ans=0
while que:
  w,s,t=heappop(que)
  root_s=find(s)
  root_t=find(t)
  if root_s!=root_t:
    pair[root_s]=root_t
    ans+=w
print(ans)

Buggy python submission (verdict: Runtime Error):
from heapq import heappop,heappush
n=int(input())
pair=[i for i in range(n)]
e=[]
que=[]
que1=[]
for i in range(n):
  s,t=map(int,input().split())
  heappush(e,(s,t))
s,t=heappop(e)
heappush(que1,(t,s,0))
for i in range(n-1):
  s1,t1=heappop(e)
  heappush(que,(s1-s,i,i+1))
  s,t=s1,t1
  heappush(que1,(t,s,i+1))
t,s,i=heappop(que1)
for _ in range(n-1):
  t1,s1,j=heappop(que1)
  heappush(que,(t1-t,i,j))
  s,t,i=s1,t1,j
def find(x):
  if x==pair[x]:return x
  else:
    tmp=find(pair[x])
    pair[x]=tmp
    return tmp
ans=0
while que:
  w,s,t=heappop(que)
  root_s=find(s)
  root_t=find(t)
  if root_s!=root_t:
    pair[root_s]=root_t
    ans+=w
print(ans)

Fixed submission:
from heapq import heappop,heappush
import sys
sys.setrecursionlimit(10**6)
n=int(input())
pair=[i for i in range(n)]
que=[]
e=[None]*n
for i in range(n):
  x,y=map(int,input().split())
  e[i]=(i,x,y)
ex=sorted(e,key=lambda x:x[1])
ey=sorted(e,key=lambda x:x[2])
for i in range(n-1):
  w=ex[i+1][1]-ex[i][1]
  heappush(que,(w,ex[i][0],ex[i+1][0]))
for i in range(n-1):
  w=ey[i+1][2]-ey[i][2]
  heappush(que,(w,ey[i][0],ey[i+1][0]))
def find(x):
  if x==pair[x]:return x
  else:
    tmp=find(pair[x])
    pair[x]=tmp
    return tmp
q=[]
ans=0
while que:
  w,s,t=heappop(que)
  root_s=find(s)
  root_t=find(t)
  if root_s!=root_t:
    pair[root_s]=root_t
    ans+=w
print(ans)

Buggy python submission (verdict: Runtime Error):
from heapq import heappop,heappush
n=int(input())
pair=[i for i in range(n)]
e=[]
que=[]
que1=[]
for i in range(n):
  s,t=map(int,input().split())
  heappush(e,(s,t))
s,t=heappop(e)
heappush(que1,(t,s,0))
for i in range(n-1):
  s1,t1=heappop(e)
  heappush(que,(s1-s,i,i+1))
  s,t=s1,t1
  heappush(que1,(t,s,i+1))
t,s,i=heappop(que1)
for _ in range(n-1):
  t1,s1,j=heappop(que1)
  heappush(que,(t1-t,i,j))
  s,t,i=s1,t1,j
def find(x):
  if x==pair[x]:return x
  else:
    tmp=find(pair[x])
    pair[x]=tmp
    return tmp
ans=0
while que:
  w,s,t=heappop(que)
  root_s=find(s)
  root_t=find(t)
  if root_s!=root_t:
    pair[root_s]=root_t
    ans+=w
print(ans)

Fixed submission:
from heapq import heappop,heappush
import sys
sys.setrecursionlimit(10**6)
n=int(input())
pair=[i for i in range(n)]
que=[]
e=[None]*n
for i in range(n):
  x,y=map(int,input().split())
  e[i]=(i,x,y)
ex=sorted(e,key=lambda x:x[1])
ey=sorted(e,key=lambda x:x[2])
for i in range(n-1):
  w=ex[i+1][1]-ex[i][1]
  heappush(que,(w,ex[i][0],ex[i+1][0]))
for i in range(n-1):
  w=ey[i+1][2]-ey[i][2]
  heappush(que,(w,ey[i][0],ey[i+1][0]))
def find(x):
  if x==pair[x]:return x
  else:
    tmp=find(pair[x])
    pair[x]=tmp
    return tmp
q=[]
ans=0
while que:
  w,s,t=heappop(que)
  root_s=find(s)
  root_t=find(t)
  if root_s!=root_t:
    pair[root_s]=root_t
    ans+=w
print(ans)