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 UnionFind:
    def __init__(self,n):
        self.n=n
        self.parents=[-1]*n
        self.rank=[0]*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 union(self,x,y):
        x=self.find(x)
        y=self.find(y)

        if x==y:
            return 

        if self.rank[x]<self.rank[y]:
            self.parents[y]+=self.parents[x]
            self.parents[x]=y
        else:
            self.parents[x]+=self.parents[y]
            self.parents[y]=x

            if self.rank[x]==self.rank[y]:
                self.rank[x]+=1

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

    def element_count(self,x):
        x=self.find(x)
        return -self.parents[x]

    def group_count(self):
        count=0
        for e in self.parents:
            if e<0: count+=1
        return count

def kruskal(n,edges):
    u=UnionFind(n)
    ans=0
    for x in edges:
        s,t,w=x
        if u.are_same(s,t)==False:
            u.union(s,t)
            ans+=w

    return ans

from sys import stdin
def main():
    #入力
    readline=stdin.readline
    v,e=map(int,readline().split())
    edges=[list(map(int,readline().split())) for _ in range(e)]
    edges.sort(key=lambda x:x[2])
    print(kruskal(v,edges))

if __name__=="__main__":
    main()