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:
def kruskal(g, size):
    g.sort(key=itemgetter(2), reverse=True)
    uf = union_find(size)
    tree = []
    while len(tree) < size - 1:
        u, v, d = g.pop()
        if not uf.union(u, v):
            tree.append((u, v, d))
    return tree

class union_find:
    def __init__(self, size):
        self.table = [-1 for _ in range(size)]

    def union(self, x, y):
        x, y = self.find(x), self.find(y)
        if x == y:return True
        
        if self.table[y] < self.table[x]:x, y = y, x

        self.table[x] += self.table[y]
        self.table[y] = x
        return False
            
    def find(self, x):
        if self.table[x] < 0:return x
        self.table[x] = self.find(self.table[x])
        return self.table[x]

from sys import stdin
from operator import itemgetter

import heapq

readline = stdin.readline


v, e = map(int, readline().split())

g = [list(map(int, readline().split())) for _ in range(e)]

tree = kruskal(g, v)

print(sum(d for s, t, d in tree))