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:
# -*- coding: utf-8 -*-

V, E = list(map(int, input().split()))
weight = []
for i in range(E):
  s, t, w = list(map(int, input().split()))
  weight.append((s,t,w))

weight.sort(key = lambda x: x[2])

parent = [i for i in range(V)]
rank = [0 for i in range(V)]

def find(x):
  if parent[x] == x:
    return x
  else:
    return find(parent[x])

def union(x, y):
  a = find(x)
  b = find(y)
  if rank[a] < rank[b]:
    parent[a] = b
  else:
    parent[b] = a
    if rank[a] == rank[b]:
      rank[a] += 1
  

sum_weight = 0

for i in range(E):
  a, b, c = weight[i]
  if find(a) != find(b):
    union(a, b)
    sum_weight += c
  else:
    continue
  
print(sum_weight)