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:
# coding: utf-8
# Your code here!

INF = 2000000000



class Node:
    def __init__(self, num):
        self.num = num
        self.parent = self
        self.rank = 0
    
def findSet(node):
    tmp = []
    while node.parent != node:
        tmp.append(node)
        node = node.parent
    
    while tmp:
        tmp.pop().parent = node
    return node

def unite(x, y):
    node1 = findSet(nodes[x])
    node2 = findSet(nodes[y])
    if node1.rank == node2.rank:
        node2.parent = node1
        node1.rank += 1
    elif node1.rank > node2.rank:
        node2.parent = node1
    else:
        node1.parent = node2

def same(x, y):
    node1 = findSet(nodes[x])
    node2 = findSet(nodes[y])
    return node1.parent == node2.parent





class Edge:
    def __init__(self, source, target, cost):
        self.source = source
        self.target = target
        self.cost = cost
    
def kruskal():
    edges.sort(key = lambda u:u.cost)
    
    for i in range(e):
        if findSet(edges[i].source) != findSet(edges[i].target):
            unite(edges[i].source.num, edges[i].target.num)
            K.append(edges[i])
    
    total = 0
    for tmp in K:
        total += tmp.cost
    print(total)


nums=list(map(int,input().split()))
n = nums[0]
e = nums[1]

edges = []
nodes = []
for i in range(n):
    nodes.append(Node(i))

for i in range(e):
    nums=list(map(int,input().split()))
    tmp = Edge(nodes[nums[0]], nodes[nums[1]], nums[2])
    edges.append(tmp)




K = []

kruskal()