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 
MOD = 10 ** 9 + 7
INF = 10**11
from heapq import heapify,heappush,heappop

def prim(n,G):
    ans = 0
    used = [0] * n
    used[0] = 1
    q = []
    for e,c in G[0]:
        heappush(q,(c,e))
    
    while len(q):
        c1,e1 = heappop(q)
        if used[e1]:
            continue
        used[e1] = 1
        for e2,c2 in G[e1]:
            if used[e2] == 0:
                heappush(q,(c2,e2))
        ans += c1
    return ans

def main():
    n,m = map(int,input().split())
    G = [[] for _ in range(n)]
    for _ in range(m):
        a,b,c = map(int,input().split())
        G[a].append((b,c))
        G[b].append((a,c))
    ans = prim(n,G)
    print(ans)
if __name__=='__main__':
    main()