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:
    sz = 0
    par = []
    def __init__(self, n):
        self.sz = n
        for i in range(n):
            self.par.append(-1)

    def find(self, a):
        if self.par[a]<0: return a
        self.par[a] = self.find(self.par[a])
        return self.par[a]
    
    def size(self, a):
        a = self.find(a)
        return -self.par[a]
    
    def same(self, a,b):
        return self.find(a) == self.find(b)

    def unite(self, a,b):
        a = self.find(a)
        b = self.find(b)
        if self.same(a,b): return False
        if self.size(a) < self.size(b):
            a,b=b,a
        self.par[a] += self.par[b]
        self.par[b] = a
        return True

n,m = map(int,input().split())
g = []
for i in range(m):
    s,t,w = map(int,input().split())
    g.append([w,s,t])
g = sorted(g)
ans = 0
uni = unionfind(n)
for c,i,j in g:
    if uni.unite(i,j): ans += c
print(ans)