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 sys import stdin

def read_edge(e):
    E = []
    for _ in range(e):
        line = stdin.readline().strip().split()
        u = line[0]
        v = line[1]
        w = line[2]
        E.append((int(w), int(u), int(v)))
    return E

class DisjointSet(object):
    def __init__(self, n):
        self.parent = [None] * (n + 1)
        self.rank = [None] * (n + 1)

    def make_set(self, x):
        if self.parent[x] == None:
            self.parent[x] = x
            self.rank[x] = 0

    def find_set(self, x):
        if x != self.parent[x]:
            self.parent[x] = self.find_set(self.parent[x])
        return self.parent[x]

    def unite(self, x, y):
        self.link(self.find_set(x), self.find_set(y))

    def link(self, x, y):
        if self.rank[x] > self.rank[y]:
            self.parent[y] = x
        else:
            self.parent[x] = y
            if self.rank[x] == self.rank[y]:
                self.rank[y] += 1

    def same(self, x, y):
        return self.find_set(x) == self.find_set(y)

def kuruskal(n, E):
    S = DisjointSet(n)
    for i in range(n):
        S.make_set(i)
    K = []
    for i in sorted(E):
        if S.find_set(i[1]) != S.find_set(i[2]):
            S.unite(i[1], i[2])
            K.append(i[0])

    return K

n, e = [ int(i) for i in input().split() ]
E = read_edge(e)
K = kuruskal(n, E)
print(sum(K))