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 = map(int,input().split(" "))
link = defaultdict(dict)
weight = defaultdict(dict)
way = [float("inf")] * vertices
for e in range(edges):
    source,target,w = map(int,input().split(" "))
    link[source] = link.get(source,set()) | {target}
    link[target] = link.get(target,set()) | {source}
    weight[source].update({target:w})
    weight[target].update({source:w})
queue = []
heapq.heapify(queue)
heapq.heappush(queue,[0,0])
went = [0] * vertices
now_weight = 0
way[0] = 0

while queue:
    here_weight,here = heapq.heappop(queue)
    #print(went)
    if went[here]:
        continue
    went[here] = 1
    now_weight += here_weight
    min_weight,next_t = float("inf"),-1
    for c in link[here]:
        if not went[c] and way[c] > weight[here][c]:
            heapq.heappush(queue,[weight[here][c],c])
            way[c] = weight[here][c]
    #print(queue)
print(now_weight)