Kruskal Algorithm

There are n vertices and there are edges in between some of the vertices. Find the sum  of edge weight of minimum spanning tree.

Input Format

First line contains number of vertices. Second line contains number of edges. Each of next E lines contain 3 number u and v and c denoting an edge between u and v with weight c.

Output Format

print the sum of edge weight of MST.

Constraints

1<= n <= 1000
1<= e <= n*(n-1)/2

Example

7
8
0 1 10
1 2 10
2 3 10
0 3 40
3 4 2
4 5 3
5 6 3
4 6 8

38