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:
class Edge:
    def __init__(self, u, v, cost):
        self.u = u
        self.v = v
        self.cost = cost
    
    def __str__(self):
        return "u: " + str(self.u) + " v: " + str(self.v) + " cost: " + str(self.cost)

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 = 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 size(self, x):
        return -self.parents[self.find(x)]
    
    def isSame(self, x, y):
        return self.find(x) == self.find(y)

def solve():
    V, E = map(int,input().split())
    edges = []
    for i in range(E):
        s,t,w = map(int,input().split())
        e = Edge(s,t,w)
        edges.append(e)
    
    edges.sort(key=lambda e: e.cost)

    uf = UnionFind(V+1)

    ans = 0
    for edge in edges:
        if not uf.isSame(edge.u, edge.v):
            uf.unite(edge.u, edge.v)
            ans += edge.cost

    print(ans)

if __name__ == '__main__':
    solve()