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

def main():
    n,m = map(int,input().split())
    e = [[] for _ in range(n)]
    for _ in range(m):
        a,b,c = map(int,input().split())
        e[a].append([b,c])
        e[b].append([a,c])

    inf = 1000000007
    d = [inf]*n
    d[0] = 0
    visited = [False]*n
    pq = [[0,0]]
    heapq.heapify(pq)
    while pq:
        c,v = heapq.heappop(pq)
        visited[v] = True
        for u,nc in e[v]:
            if not visited[u] and nc < d[u]:
                d[u] = nc
                heapq.heappush(pq,[nc,u])

    res = 0
    for i in range(n):
        res+=d[i]
    print(res)


if __name__ == '__main__':
    main()