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

V,E = map(int, input().split())

es = [[] for _ in range(V)]
q = []
for _ in range(E):
    s,t,w = map(int, input().split())
    heapq.heappush(q, (w,s,t))

class UnionFind:
    def __init__(self, N):
        self.parent = [i for i in range(N)]
        self.rank = [0] * N # 最初はそれぞれのノードが誰ともUnionをつくってないから木の深さが０
        self.count = 0 # unite回数
    
    # 根を返す
    def root(self, a):
        if self.parent[a] == a:
            return a
        else:
            # 親を見に行く
            self.parent[a] = self.root(self.parent[a])
            return self.parent[a]
    
    # 同じUnionに属するかどうか
    def is_same(self, a, b):
        return self.root(a) == self.root(b)
    
    # 同じUnionにする
    def unite(self, a, b):
        ra = self.root(a)
        rb = self.root(b)
        if ra == rb:
            return 
        if self.rank[ra] < self.rank[rb]:
            self.parent[ra] = rb
        else:
            self.parent[rb] = ra
            if self.rank[ra] == self.rank[rb]:
                self.rank[ra] += 1
        self.count += 1

uf = UnionFind(V)
total = 0
while q:
    w,s,t = heapq.heappop(q)
    if not uf.is_same(s,t):
        uf.unite(s,t)
        total += w

print(total)