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

INF = 10 ** 20

v_num, e_num= map(int, input().split())
edges_lst = [[] for _ in range(v_num)]
dist_lst = [INF for _ in range(v_num)]

min_dis = INF
for _ in range(e_num):
    s, t, dist = map(int, input().split())
    edges_lst[s].append((dist, t))
    edges_lst[t].append((dist, s))
    if min_dis > dist:
        min_dis = dist
        node1,node2 = s,t
    
if v_num==1:
    print(0)
else:
    que = []
    for v in edges_lst[node1]:
        heappush(que, v)
    for v in edges_lst[node2]:
        heappush(que, v)
        S = {node1,node2}
        ans = min_dis


    while len(S)!=v_num:
        dist, node = heappop(que)
        if node not in S:
            S.add(node)
            ans += dist
            for dist2 ,v in edges_lst[node]: 
                if v not in S:
                    heappush(que, (dist2, v))

    print(ans)