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:
import sys
import heapq


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


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


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


def same(x, y):
    x = find_set(x)
    y = find_set(y)
    if x == y:
        return True
    else:
        return False


h = []

line = sys.stdin.readline()
v, e = map(int, line.split())
p = [i for i in range(v)]
rank = [0 for _ in range(v)]

for i in range(e):
    line = sys.stdin.readline()
    s, t, w = map(int, line.split())
    heapq.heappush(h, (w, s, t))

s = 0
for i in range(e):
    elm = heapq.heappop(h)
    if not same(elm[1], elm[2]):
        s = s + elm[0]
        unite(elm[1], elm[2])

print(s)