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:
par , rank = [],[] #par[x] = yでxの親がyであることを表す rank[x]はxが属する木の高さ

def find(x):#xの根を求める
    if par[x] == x : return x
    else:
        par[x] = find(par[x])
        return par[x]

def unite(x,y): #x,yが属する集合を合併
    x = find(x)
    y = find(y)
    if (x != y):
        if rank[x] < rank[y]:
            par[x] = y
        else :
            par[y] = x
            if (rank[x] == rank[y]) : rank[x] += 1

v,e = map(int, input().split())

edge = []

for i in range(e):
    s,t,w = map(int, input().split())
    edge.append((w,s,t))

edge.sort()
mincost = 0

for i in range(v): #初期化　任意の要素が根 
    par.append(i)
    rank.append(0)

for ee in edge:
    w,s,t = ee
    if (find(s) != find(t)) :
        unite(s,t)
        mincost += w

print(mincost)