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:
import heapq

def find_root(x):
  if x == nodes[x]:
    return x
  else:
    root = nodes[x] = find_root(nodes[x])
    return root

nv, ne = map(int, input().split())
nodes = [i for i in range(nv)]
q = []

for _ in range(ne):
  s, t, w = map(int, input().split())
  heapq.heappush(q, (w, s, t))

sum = 0

while q:
  w, s, t = heapq.heappop(q)
  root_s = find_root(s)
  root_t = find_root(t)
  if root_s != root_t:
    nodes[root_s] = root_t
    sum += w

print(sum)