WA in BLINNET using python 3

Anyone who solved this please help me with the code. Is my I/O operations correct? I used the same approach for a similar problem in hackerrank and it passed all the test cases even with 10000 edges.

import heapq
from collections import defaultdict
def Find(Parent,U):
  if Parent[U]==-1:
    return U
  return Find(Parent,Parent[U])

def Union(Parent,U,V):
  Parent[Find(Parent,U)]=Find(Parent,V)

def hasCycle(Graph,Parent):
  for i in Graph:
    for node in Graph[i]:
      if Find(Parent,node)==Find(Parent,i):
        return True
      else:
        Union(Parent,node,i)
  return False

def Kruskal(Graph,N):
  Parent={i:-1 for i in range(1,N+1)}
  MST=0
  edges=0
  while edges<N-1:
    W,U,V=heapq.heappop(Graph)
    if Find(Parent,U)!=Find(Parent,V):
      edges+=1
      MST+=W
      Union(Parent,U,V)
  return MST

try:
  for i in range(int(input())):
    Graph=[]
    temp_graph=defaultdict(list)
    empty=input()
    N=int(input())
    for U in range(1,N+1):
      city=input()
      for niegh in range(int(input())):
        V,W=map(int,input().split())
        if V>U:
          heapq.heappush(Graph,(W,U,V))
    print(Kruskal(Graph,N))
except:
  flag=False