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 heappush, heappop, heapify
def prim(n, graph):
    used = [False] * n
    hq = [(w, v) for v, w in graph[0]]
    heapify(hq)
    used[0] = True
    res = 0
    while hq:
        w, v = heappop(hq)
        if used[v]:
            continue
        used[v] = True
        res += w
        for cv, cw in graph[v]:
            if used[cv]:
                continue
            heappush(hq, (cw, cv))
    return res

V, E = map(int, input().split())
graph = [[] for _ in range(V)]
for _ in range(E):
    s, t, w = map(int, input().split())
    graph[s].append((t, w))
    graph[t].append((s, w))
print(prim(V, graph))