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
inf=float("inf")


def prim():
    color=["white" for _ in range(v)]
    D=[inf for _ in range(v)]
    M=[[] for _ in range(v)]

    for s,t,w in STW:
        M[s].append([w,t])
        M[t].append([w,s])

    queue=[[0,0]]
    _heapq.heapify(queue)
    color[0]="gray"
    D[0]=0

    while len(queue)>0:
        num=_heapq.heappop(queue)[1]
        if color[num]=="black":continue
        color[num]="black"

        for i,j in M[num]:
            if i<D[j] and color[j]!="black":
                color[j]="gray"
                D[j]=i
                _heapq.heappush(queue,[i,j])

    return D


v,e=map(int,input().split())
STW=[list(map(int,input().split())) for _ in range(e)]
print(sum(prim()))