Given a connected, weighted, undirected graph of n vertices and m edges. Find weight of its minimum spanning tree.
_A minimum spanning tree (MST) or minimum weight spanning tree is a subset of the edges of a connected, edge-weighted undirected graph that connects all the vertices together, without any cycles and with the minimum possible total edge weight._
### Input
- The first line contain 2 integers n,m.
- The next m lines, each line contains 3 integers u,v,w, there is an edge weigh w between u and v.
### Output
- Print the weight of the minimum spanning tree.
### Constraints
- 1≤n,m≤105.
- 1≤u,v≤n.
- 1≤w≤109.
### Example
Input:
33121232313
Output:
3
