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:
def find(x):
    if vertices[x] != x:
        vertices[x] = find(vertices[x])
    return vertices[x]

nv, ne = map(int, input().split(' '))
vertices = [i for i in range(nv)]
edges = []
for i in range(ne):
    s, t, w = map(int, input().split(' '))
    edges.append((s, t, w))

sum = 0
forest = [[v] for v in range(nv)]
edges.sort(key=lambda tup: tup[2])
for s, t, w in edges:
    u = find(s)
    v = find(t)
    if u != v:
        vertices[u] = v
        sum += w

print(sum)