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
import heapq
vertices, edges = (int(n) for n in input().split(" "))
conn = defaultdict(set)
weight = defaultdict(dict)
for i in range(edges):
    v1, v2, w = (int(n) for n in input().split(" "))
    conn[v1] |= {v2}
    conn[v2] |= {v1}
    weight[v1][v2] = w
    weight[v2][v1] = w

queue = []
heapq.heapify(queue)
heapq.heappush(queue, [0,0])
went = set()
went_vertices = 0
answer_weight = 0
while went_vertices < vertices:
    here_weight, here_v = heapq.heappop(queue)
    if here_v in went:
        continue
    went |= {here_v}
    for c in conn[here_v]:
        if c not in went:
            heapq.heappush(queue,[weight[here_v][c], c])
    answer_weight += here_weight
    went_vertices += 1
print(answer_weight)