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
H = []
V, E = map(int, input().split())
#G = [[] for _ in range(V)]
for _ in range(E):
    s, t, w = map(int, input().split())
    #G[s].append((t, w))
    heapq.heappush(H, (w, s, t))


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

    def root(self, a):
        if self.parent[a] < 0:
            return a
        else:
            self.parent[a] = self.root(self.parent[a])
            return self.parent[a]

    def size(self, a):
        return - self.parent[self.root(a)]

    def connect(self, a, b) -> bool:
        a = self.root(a)
        b = self.root(b)

        if a == b:
            return False

        if self.size(a) < self.size(b):
            a, b = b, a

        self.parent[a] += self.parent[b]
        self.parent[b] = a
        return True


unif = UnionFind(V)
ans = 0
while len(H) > 0:
    w, s, t = heapq.heappop(H)
    if unif.root(s) == unif.root(t):
        continue

    unif.connect(s, t)
    ans += w

print(ans)