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:
import sys
import time
input = sys.stdin.readline

def find(tree,x):
    idx = tree[x][0]
    if(idx== x):
        return x
    else:
        root_idx = find(tree,idx)
        return root_idx

def unite(tree,x,y,w):
    x_root_idx = find(tree,x)
    y_root_idx = find(tree,y)

    if not (x_root_idx == y_root_idx):
        if(tree_rank[x_root_idx] < tree_rank[y_root_idx]):
            tree[x_root_idx] = (y_root_idx,w)
        else:
            tree[y_root_idx] = (x_root_idx,w)
            if(tree_rank[x_root_idx] == tree_rank[y_root_idx]):
                tree_rank[x_root_idx] = tree_rank[x_root_idx] + 1

def same(tree,x,y):
    x_root_idx = find(tree,x)
    y_root_idx = find(tree,y)
    if(x_root_idx == y_root_idx):
        return True
    else:
        return False

v_num,e_num = map(int, input().split())
edges = [list(map(int, input().split())) for i in range(e_num)]
union_find_tree = [(i,0) for i in range(v_num)]
tree_rank = [0]*v_num
if __name__ == "__main__":
    edges.sort(key=lambda x:x[2])
    for e in edges:
        unite(union_find_tree,e[0],e[1],e[2])
    print(sum(item[1] for item in union_find_tree))