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 heapq import heappop, heappush
v_num, e_num = map(int, input().split())
pair_lst = [i for i in range(v_num)]
que = []
for _ in range(e_num):
  s, t, w = map(int, input().split())
  heappush(que, (w, s, t))
def find(x):
  if x == pair_lst[x]:
    return x
  else:
    tmp = find(pair_lst[x])
    pair_lst[x] = tmp
    return tmp

length_sum = 0
while que:
  w, s, t = heappop(que)
  root_s = find(s)
  root_t = find(t)
  if root_s != root_t:
    pair_lst[root_s] = root_t
    length_sum += w

print(length_sum)