Minimum spanning tree

Find the weight of minimum spanning tree for a weighted undirected connected graph.

Input

The first line contains the numbers $n$ and $m(1\le n\le 100,1\le m\le 6000)$, where $n$ is the number of vertices in the graph and $m$ is the number of edges. Each of the next $m$ lines contains a triple of integers $a,b,c$, where $a$ and $b$ are the numbers of vertices connected by an edge and $c$ is the weight of edge (a positive number not exceeding $30000$).

Output

Print the weight of minimum spanning tree.

Examples