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 as pq
n,E = map(int, input().split())
M = [[] for i in range(n)]
for i in range(E):
 s,t,w = map(int, input().split())
 M[s].append([t,w])
 M[t].append([s,w])

def prim():
 color = [0] * n
 d = [float("inf")] * n
 d[0] = 0
 H = []
 pq.heappush(H, [0, 0])
 while H:
  u2,u1 = pq.heappop(H)
  color[u1] = 1
  if d[u1] < u2: continue
  for v1, v2 in M[u1]:
   if color[v1] == 1: continue
   if d[v1] > v2:
    d[v1] = v2
    pq.heappush(H, [d[v1], v1])
 return sum(d)
 
print(prim())