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:
class UF():
  def __init__(self, n):
    self.parents = [-1] * n

  def find(self,n):
    if self.parents[n] < 0:
      return n
    else:
      self.parents[n] = self.find(self.parents[n])
      return self.parents[n]

  def union(self, u, v):
    p1, p2 = self.find(u), self.find(v)
    if p1 == p2: return

    if self.parents[p1] > self.parents[p2]:
      p1,p2 = p2,p1

    self.parents[p1] += self.parents[p2]
    self.parents[p2] = p1

  def same(self, u, v):
    return self.find(u) == self.find(v)

V,E = map(int,input().split())
edges = []
for i in range(E):
  s,t,w = map(int,input().split())
  edges.append((w,s,t))
edges.sort(key=lambda x: x[0])

uf = UF(V)
ans = 0
for i in range(E):
  w,s,t = edges[i]
  if not uf.same(s,t):
    uf.union(s,t)
    ans += w

print(ans)