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 heapq


class UnionFind:
    from collections import deque

    def __init__(self, v):
        self.v = v
        self._tree = list(range(v + 1))

    def _root(self, a):
        queue = self.deque()
        while self._tree[a] != a:
            queue.append(a)
            a = self._tree[a]
        while queue:
            index = queue.popleft()
            self._tree[index] = a
        return a

    def union(self, a, b):
        root_a = self._root(a)
        root_b = self._root(b)
        self._tree[root_b] = root_a

    def find(self, a, b):
        return self._root(a) == self._root(b)


V, E = map(int, input().split(' '))
heap = []
for _ in range(E):
    s, t, w = map(int, input().split(' '))
    heapq.heappush(heap, (w, s, t))

uf = UnionFind(V)
cost = 0
while heap:
    w, s, t = heapq.heappop(heap)
    if not uf.find(s, t):
        uf.union(s, t)
        cost += w

print(cost)