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 sys
import collections
sys.setrecursionlimit(10**7)


def init(n):
    return list(range(n+1))

def find(lis, x):
    if lis[x] == x:
        return x
    else:
        lis[x] = find(lis, lis[x])
        return lis[x]

def sameset(lis, x, y):
    return find(lis, x) == find(lis, y)

def union(lis, x, y):
    x = find(lis, x)
    y = find(lis, y)
    if x != y:
        lis[x] = y

V,E=map(int,input().split())
union_find_tree = init(V)
graph = []
for _ in range(E):
    s, t, w = map(int, input().split())
    graph.append((s,t,w))

cost = 0
for (s,t,w) in sorted(graph, key=lambda x: x[2]):
    if not sameset(union_find_tree,s,t):
        union(union_find_tree,s,t)
        cost += w
print(cost)