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:
# e1 will be less than e2
def ifcycle(e1,e2):
    while uf[e1]>=0:
        e1=uf[e1]
    while uf[e2]>=0:
        e2=uf[e2]
    if e1==e2:
        return True
    if uf[e1]<=uf[e2]:
        uf[e1]+=uf[e2]
        uf[e2]=e1
    else:
        uf[e2]+=uf[e1]
        uf[e1]=e2
        return False
    
    
x,y=map(int,input().split())
a=[]
# for union-find
uf=[-1]*x
for i in range(y):
    v1,v2,v3=map(int,input().split())
    a.append([v3,v1,v2])
a.sort() 
ans=0 ; cnt=0
for p in range(y):
    w,s,t=a[p]
    if not ifcycle(s,t):
        ans+=w
        cnt+=1
        if cnt>=x: print(w)

print(ans)