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 heappop,heappush
inf = float("inf")
white = 0; gray = 1; black =2

def prim():
    mindist[0] = 0 
    PQ = [(0,0)]
    while PQ:
        minw,s = heappop(PQ)
        color[s] = black
        if mindist[s] < minw: continue
        for t,w in G[s]:
            if color[t] == black: continue
            if w < mindist[t]:
                mindist[t] = w
                color[t] = gray
                heappush(PQ,(w,t))
    return sum(mindist)

V,E = map(int,input().split())
G = [[] for _ in range(V)]
for _ in range(E):
    s,t,w = map(int,input().split())
    G[s].append((t,w))
    G[t].append((s,w))
color = [white]*V
mindist = [inf]*V
print(prim())