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

from heapq import heappush, heappop
edges = []
for _ in range(e):
    s, t, w = map(int, input().split())
    heappush(edges, (w, s, t))

# initialize
par = [-1] * v
rank = [0] * v
# Union Find Tree
def find(x):
    """ 根ノードの値を見つけて返す """
    if par[x] < 0:
        return x
    else:
        par[x] = find(par[x])
        return par[x]

def unite(x, y):
    """xとyを結合する"""
    rootx = find(x)
    rooty = find(y)

    if rootx == rooty:
        return False
    else:
        if rank[rootx] < rank[rooty]:
            par[rootx] = rooty
        else:
            par[rooty] = rootx
            if rank[rootx] == rank[rooty]: rank[rootx] += 1
        return True

def same(x, y):
    """ xとyが同じ集合に属しているか """
    return find(x) == find(y)

ans = 0
while edges:
    w, s, t = heappop(edges)
    if not same(s, t):
        ans += w
        unite(s, t)

print(ans)