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 heapq

def makeSet(x):
    p[x] = x
    rank[x] = 0

def union(x, y):
    link(findSet(x), findSet(y))

def link(x, y):
    if rank[x] > rank[y]:
        p[y] = x
    else:
        p[x] = y
        if rank[x] == rank[y]:
            rank[y] += 1

def findSet(x):
    if x != p[x]:
        p[x] = findSet(p[x])
    return p[x]



v,e = map(int, input().split())
edge = [[] for _ in range(v)]

p = [0]*v
rank = [0]*v
for x in range(v):
    makeSet(x)

S = []
ans = 0
for _ in range(e):
    s,t,w = map(int, input().split())
    heapq.heappush(S, [w, s, t])
    
while S:
    w,s,t = heapq.heappop(S)
    if findSet(s) != findSet(t):
        union(s,t)
        ans += w
print(ans)