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

sys.setrecursionlimit(10 ** 7)
input = sys.stdin.readline
f_inf = float('inf')
mod = 10 ** 9 + 7


class UnionFind:
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        """
        親が同じか判別する
        """
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        """
        yをxの根に繋ぐ
        """
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return
        if self.parents[x] > self.parents[y]:
            x, y = y, x
        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def same(self, x, y):
        """
        xとyが同じ連結成分か判別する
        """
        return self.find(x) == self.find(y)

    def size(self, x):
        """
        xの連結成分の大きさを返す
        """
        return -self.parents[self.find(x)]

    def kruskal(self, edge):
        """
        :param edge: edge = [(コスト, 頂点1, 頂点2),...]の形で重み付き隣接リストを渡して下さい
        :return: 最小全域木のコストの和
        """
        edge.sort()
        cost_sum = 0
        for cost, node1, node2 in edge:
            if not self.same(node1, node2):
                cost_sum += cost
                self.union(node1, node2)
        return cost_sum


def resolve():
    V, E = map(int, input().split())
    edge = []
    for _ in range(E):
        s, t, w = map(int, input().split())
        edge.append([w, s, t])

    uf = UnionFind(V)
    res = uf.kruskal(edge)
    print(res)


if __name__ == '__main__':
    resolve()