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


class UnionFind:

    def __init__(self, nvertices):
        self.rank = [1] * (nvertices + 5)
        self.p = [i for i in range(nvertices + 5)]

    def find_set(self, u):
        if u != self.p[u]:
            self.p[u] = self.find_set(self.p[u])
        return self.p[u]

    def unite(self, u, v):
        x = self.find_set(u)
        y = self.find_set(v)
        if x == y:
            return
        if self.rank[x] > self.rank[y]:
            self.p[y] = x
        else:
            self.p[x] = y
            if self.rank[x] == self.rank[y]:
                self.rank[y] += 1

    def is_connected(self, u, v):
        return self.find_set(u) == self.find_set(v)


def main():
    sys.setrecursionlimit(int(1e5))
    nvertices, nedges = map(int, input().split())
    edges = []
    for i in range(nedges):
        u, v, w = map(int, input().split())
        edges.append((w, u, v))

    edges.sort(key=lambda e: e[0])
    ans = 0
    uf = UnionFind(nvertices)
    for w, u, v in edges:
        if not uf.is_connected(u, v):
            uf.unite(u, v)
            ans += w

    print(ans)


main()