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:
class DisjointSetElement():
    def __init__(self, x):
        self.parent = x
        self.rank = 0


class DisjointSet():
    def __init__(self, n):
        self.elems = [DisjointSetElement(n) for n in range(n)]

    def _find_set(self, x):
        if x != self.elems[x].parent:
            self.elems[x].parent = self._find_set(self.elems[x].parent)
        return self.elems[x].parent

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

    def _link(self, x, y):
        if self.elems[x].rank > self.elems[y].rank:
            self.elems[y].parent = x
        else:
            self.elems[x].parent = y
            if self.elems[x].rank == self.elems[y].rank:
                self.elems[y].rank += 1

    def unite(self, x, y):
        self._link(self._find_set(x), self._find_set(y))

    def is_alone(self, x):
        return x == self.elems[x].parent


def read_inputs():
    nv, ne = [int(x) for x in input().split()]

    E = []
    for _ in range(ne):
        s, t, w = [int(x) for x in input().split()]
        E.append((w, s, t))

    return nv, E


def min_sp_tree(nv, E):
    K = DisjointSet(nv)
    total = 0
    n = 0

    i = iter(E)
    while n < nv - 1:
        w, s, t = next(i)
        if not K.same(s, t):
            K.unite(s, t)
            total += w
            n += 1

    return total


def main():
    nv, E = read_inputs()
    E.sort()
    print(min_sp_tree(nv, E))


if __name__ == '__main__':
    main()