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 PYTHON):

Solution:
from heapq import heappush, heappop

V, E = map(int, raw_input().split())
parent = range(V)
def root(x):
    if parent[x] != x:
        x = parent[x] = root(parent[x])
    return x
def unite(x, y):
    rx = root(x); ry = root(y)
    if rx < ry:
        parent[ry] = rx
    else:
        parent[rx] = ry
def same(x, y):
    return root(x) == root(y)
que = []
for i in xrange(E):
    s, t, w = map(int, raw_input().split())
    heappush(que, (w, s, t))

ans = 0
while que:
    w, s, t = heappop(que)
    if not same(s, t):
        unite(s, t)
        ans += w
print ans