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 PYTHON):

Solution:
class Edge():
    def __init__(self, src, to, weight):
        self.src = src
        self.to = to
        self.weight = weight

    def __lt__(self, other):
        return self.weight < other.weight

class Edges():
    def __init__(self):
        self.E = []
    
    def append(self, src, to, weight=0):
        self.E.append(Edge(src, to, weight))

    def getInOrderByASC(self):
        return sorted(self.E)

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

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def unite(self, x, y):
        x, y = self.find(x), 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):
        return self.find(x) == self.find(y)

    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]
        
    def __str__(self):
        return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())


class MinimumSpanningTree():
    def __init__(self, V, edges):
        self.V = V
        self.E = edges

    # O(E*log(V))
    def kruskal(self):
        U = UnionFind(self.V)
        total = 0
        for e in self.E.getInOrderByASC():
            if not U.same(e.src, e.to):
                total += e.weight
                U.unite(e.src, e.to)
        return total


V,E = map(int, raw_input().split())
edges = Edges()
for i in range(E):
    s,t,w = map(int, raw_input().split())
    edges.append(s,t,w)

mst = MinimumSpanningTree(V, edges)
print mst.kruskal()