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 PYTHON):

Solution:
import sys
from heapq import heappush, heappop

class UFSet:
    def __init__(self, n):
        self.fa = [i for i in range(n)]
        
    def find(self, v):
        if v != self.fa[v]:
            self.fa[v] = self.find(self.fa[v])
        return self.fa[v]
    
    def union(self, a, b):
        pa = self.find(a)
        pb = self.find(b)
        self.fa[pa] = pb
        

def kruscal(Edges, V):
    ufset = UFSet(V)
    ret = 0
    
    for w, a, b in Edges:
        pa, pb = ufset.find(a), ufset.find(b)
        if pa == pb:
            continue
        else:
            ret += w
            ufset.union(pa, pb)
    
    return ret
            
    
    
if __name__ == '__main__':
    line = sys.stdin.readline()
    V, E = line.split()
    V, E = int(V), int(E)
    
    Es = []
    
    for i in range(E):
        line = sys.stdin.readline()
        a, b, w = line.split()
        a, b, w = int(a), int(b), int(w)
        Es.append((w, a, b))
    
    Es.sort()
        
        
    sys.stdout.write(str(kruscal(Es, V)) + '\n')