Problem: Find the sum of weights of edges of the Minimum Spanning Tree for a given weighted undirected graph G = (V, E).

Constraints

* 1 ≤ |V| ≤ 10,000
* 0 ≤ |E| ≤ 100,000
* 0 ≤ wi ≤ 10,000
* The graph is connected
* There are no parallel edges
* There are no self-loops

Input


|V| |E|
s0 t0 w0
s1 t1 w1
:
s|E|-1 t|E|-1 w|E|-1


, where |V| is the number of vertices and |E| is the number of edges in the graph. The graph vertices are named with the numbers 0, 1,..., |V|-1 respectively.

si and ti represent source and target verticess of i-th edge (undirected) and wi represents the weight of the i-th edge.

Output

Print the sum of the weights of the Minimum Spanning Tree.

Examples

Input

4 6
0 1 2
1 2 1
2 3 1
3 0 1
0 2 3
1 3 5


Output

3


Input

6 9
0 1 1
0 2 3
1 2 1
1 3 7
2 4 1
1 4 3
3 4 1
3 5 1
4 5 6


Output

5

Solution (in PYTHON3):

Solution:
from collections import defaultdict
from heapq import heappush, heappop
INF = 9999999999999999999999999999

def spanning_tree(G):
  n = len(G)
  T = {}
  added = set([0])
  heap = []
  for v in G[0]:
    heappush(heap, (G[0][v], (0, v)))
  while len(added) < n:
    while True:
      c, e = heappop(heap)
      if e[1] not in added:
        break
    T[e] = c
    added.add(e[1])
    for v in G[e[1]]:
      heappush(heap, (G[e[1]][v], (e[1], v)))

  return T


G = {}

n, m = [int(v) for v in input().strip().split(' ')]
for i in range(n):
  G[i] = {}
for _ in range(m):
  s, t, c = [int(v) for v in input().strip().split(' ')]
  G[s][t] = c
  G[t][s] = c

if m == 0:
  print(0)
  exit()

T = spanning_tree(G)

s = 0
for e in T:
  s += T[e]

print(s)