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:
class UnionFind():
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n
        
    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]
    
    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        
        if x == y:
            return
        
        if self.parents[x] > self.parents[y]:
            x, y = y, x
        
        self.parents[x] += self.parents[y]
        self.parents[y] = x
    
    def size(self, x):
        return -self.parents[self.find(x)]
        
    def same(self, x, y):
        return self.find(x) == self.find(y)
    
    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]
    
    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())
    
    def all_group_members(self):
        return {r: self.members(r) for r in self.roots()}
    
    def __str__(self):
        return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())

v, e = map(int,input().split())
road = []
for i in range(e):
    a, b, c = list(map(int,input().split()))
    road.append((a,b,c))
road.sort(key = lambda x: x[2])
#print(road)

uf = UnionFind(v)
cost = 0
cnt = 0
for i in range(e):
    a = road[i][0]
    b = road[i][1]
    c = road[i][2]
    if uf.same(a,b) == False:
        uf.union(a,b)
        cost += c
        cnt += 1
        if cnt == v-1:
            break
#print("cost =", cost)
print(cost)