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(object):
    def __init__(self, n):
        self.parent={i:i for i in range(1,n+1)}
        self.size={i:1 for i in range(1,n+1)}
    def find(self, a):
        if self.parent[a]!=a:
            self.parent[a]=self.find(self.parent[a])
        return self.parent[a]
    def getsize(self, a):
        return self.size[self.find(a)]
    def unite(self, a, b):
        a=self.find(a)
        b=self.find(b)
        if a==b:return
        if self.size[a]>self.size[b]:
            self.size[a]+=self.size[b]
            self.parent[b]=a
        else:
            self.size[b]+=self.size[a]
            self.parent[a]=b
    def isunited(self, a, b):
        return self.find(a)==self.find(b)


V, E = map(int, input().split())
uft = UnionFind(V)
l = [tuple(map(int, input().split())) for _ in range(E)]
l.sort(key=lambda x:x[2])

ans = 0
for s, t, w in l:
    s += 1; t += 1
    if not uft.isunited(s, t):
        ans += w
        uft.unite(s, t)

print(ans)