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 PYTHON):

Solution:
import heapq

def prim(n, path):
  selected = {}
  paths = []
  hq = []
  selected[0] = True

  if 0 not in path:
    return []

  for s,d,w in path[0]:
    heapq.heappush(hq, (w, [0,d,w]))

  while len(hq) != 0:
    k,root = heapq.heappop(hq)
    if root[1] in selected: continue
    selected[root[1]] = True
    paths.append(root)
    for s,d,w in path[root[1]]:
      heapq.heappush(hq, (w, [s,d,w]))
  return paths

V,E = map(int, raw_input().split())
path = {}
for _ in xrange(E):
  s,t,w = map(int, raw_input().split())
  if s not in path:
    path[s] = []
  path[s].append([s,t,w])
  if t not in path:
    path[t] = []
  path[t].append([t,s,w])
result = prim(V, path)
sumcost = 0
for s,d,v in result:
  sumcost += v
print sumcost