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:

n, m = map(int, input().split())
stw = [list(map(int, input().split())) for _ in range(m)]
stw = sorted(stw, key=lambda x:x[2])

class UnionFind():
  def __init__(self, n):
    self.n = n
    self.root = [-1]*(n+1)
    self.rnk = [0]*(n+1)
  def Find_Root(self, x):
    if(self.root[x] < 0):
      return x
    else:
      self.root[x] = self.Find_Root(self.root[x])
      return self.root[x]
  def Unite(self, x, y):
    x = self.Find_Root(x)
    y = self.Find_Root(y)
    if(x == y):
      return 
    if self.root[x] > self.root[y]:
      x, y = y, x
    self.root[x] += self.root[y]
    self.root[y] = x 
  def isSameGroup(self, x, y):
    return self.Find_Root(x) == self.Find_Root(y)
  def Count(self, x): # xが属するグループのサイズを返す
    return -self.root[self.Find_Root(x)]
  def Members(self, x): # xが属するグループに属する要素をリストで返す
    return [i for i in range(self.n) if self.Find_Root(i)==self.Find_Root(x)]
  def Roots(self): # 全ての根の要素をリストで返す
    return [i for i, x in enumerate(self.root) if x < 0]
  def Group_Count(self): # グループの数を返す
    return len(self.Roots())

def kruskal():
  res = 0 
  uf = UnionFind(n)
  for i in range(m):
    s, t, w = stw[i]
    if not uf.isSameGroup(s, t):
      uf.Unite(s, t)
      res += w 
  
  return res

print(kruskal())