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:
#!python3

import sys
iim = lambda: map(int, sys.stdin.readline().rstrip().split())

def resolve():
    it = map(int, sys.stdin.read().split())
    V, E = next(it), next(it)

    ee = [-1] * V
    def find(a):
        q = []
        while ee[a] >= 0:
            q.append(a)
            a = ee[a]
        for i in q:
            ee[i] = a
        return a
    def union(a, b):
        ai = find(a)
        bi = find(b)

        r1, r2 = ee[ai],  ee[bi]
        if r1 > r2:
            ai, bi = bi, ai

        ee[bi] = ai
        if r1 == r2:
            ee[ai] -= 1
    def same(a, b):
        ai = find(a)
        bi = find(b)

        return ai == bi

    ans = 0
    for si, ti, wi in sorted(zip(it, it, it), key=lambda x: x[2]):
        if same(si, ti):
            continue
        ans += wi
        union(si, ti)

    print(ans)

if __name__ == "__main__":
    resolve()