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:
# 2019/07/10

from heapq import heappop,heappush

n,m=map(int,input().split())
edge=[[] for _ in range(n)]
for i in range(m):
    u,v,c=map(int,input().split())
    edge[u].append((c,v))
    edge[v].append((c,u))


def prim(s):
    d=[float('inf')]*n
    visited=[False]*n
    d[s]=0
    visited[s]=True
    que=[]
    for e in edge[s]:
        heappush(que,e)
    while que:
        c,v=heappop(que)
        if visited[v]:continue
        d[v]=c
        visited[v]=True
        for cost,vtx in edge[v]:
            if visited[vtx]:continue
            hq=(cost,vtx)
            heappush(que,hq)
    return d


print(sum(prim(0)))