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:
num_v,num_e=input().split()

edges=[]
verticies=[]

for i in range(int(num_e)):
    v,u,w=input().split()
    e=(v,u,int(w))
    edges.append(e)


for v in range(int(num_v)):
    v=str(v)
    verticies.append(v)

#for i in range(num_e):
#    e=(e_list[i*3],e_list[i*3+1],int(e_list[i*3+2]))
#    edges.append(e)

graph={
    'verticies':verticies,
    'edges':edges
}


parent={}
g_len={}

def group(v):
    parent[v]=v
    g_len[v]=0

def my_parent(v):
    if parent[v]!=v:
        parent[v]=my_parent(parent[v])
    return parent[v]
    
    
def union(v, u): 
    g_v=my_parent(v)
    g_u=my_parent(u)
    if g_v != g_u:
        if g_len[g_v] >= g_len[g_u]:
            parent[g_u]=parent[g_v]
            g_len[g_v] +=1
        else:
            parent[g_v]=parent[g_u]
            g_len[g_u] +=1
            

def kruskal(graph):
    g_list=[]
    sum_w=0
    
    for v in graph['verticies']:
        group(v)
        
    edges=graph['edges']
    edges.sort(key=lambda edges:edges[2])
    
    for edge in edges:
        v, u, weight =edge
        
        if my_parent(v) != my_parent(u):
            union(v,u)
            g_list.append(edge)
            sum_w=sum_w + weight
            
    return sum_w
    

print(kruskal(graph))