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 *
def prim_heap():
    used = [False] * n
    e_lst = []
    for e in edge[0]:
        heappush(e_lst,e)
    used[0] = True
    res = 0
    while e_lst:
        e_min = heappop(e_lst)
        v = e_min[1]
        if used[v]: continue
        used[v] = True
        for e in edge[v]:
            if not used[e[1]]:
                heappush(e_lst, e)
        res += e_min[0]
    return res

n, k = map(int, input().split())
edge = [[] for _ in range(n)]
for _ in range(k):
    s, t, w = map(int, input().split())
    edge[s].append((w, t))
    edge[t].append((w, s))
print(prim_heap())