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 PYTHON):

Solution:
class UnionFind:
    def __init__(self, size):
        self.rank = [0] * size
        self.par = range(size)
        self.g_num = size

    def find(self, x):
        if x == self.par[x]: return x
        self.par[x] = self.find(self.par[x])
        return self.par[x]

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

    def unite(self, x, y):
        x, y = self.find(x), self.find(y)
        if x == y: return

        self.g_num -= 1
        if (self.rank[x] > self.rank[y]):
            self.par[y] = x
        else:
            self.par[x] = y
            if (self.rank[x] == self.rank[y]): self.rank[y] += 1

    def group_num(self):
        return self.g_num



V, E = map(int, raw_input().split())
es = [map(int, raw_input().split()) for i in xrange(E)]
es.sort(key = lambda x: x[2])

uf = UnionFind(V)
ans = 0
for e in es:
    if not uf.same(e[0], e[1]):
        uf.unite(e[0], e[1])
        ans += e[2]
print ans