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:
# Minimum Spanning Tree
p = []
rank = []
edge = []
cost = 0

def makeSet(x):
    global p, rank
    p.append(x)
    rank.append(0)

def findSet(x):
    global p
    if x != p[x]:
        p[x] = findSet(p[x])
    return p[x]

def link(x, y):
    global p, rank
    if rank[x] > rank[y]:
        p[y] = x
    else:
        p[x] = y
        if rank[x] == rank[y]:
            rank[y] += 1

def union(x, y):
    link(findSet(x), findSet(y))    

def same(x, y):
    if findSet(x) == findSet(y):
        return 1
    else:
        return 0   

[v, e] = list(map(int, input().split()))
for i in range(v):
    makeSet(i)

for i in range(e):
    [s, t, w] = list(map(int, input().split()))
    edge.append([w, s, t])

edge.sort()

while v > 1:
    min = edge.pop(0)
    if not same(min[1], min[2]):
        union(min[1], min[2])
        cost += min[0]
        v -= 1

print(cost)