You are tasked with finding the Minimum Spanning Tree of a Graph.

Input Format

The first line of input will consist of two integers, ~n~ and ~m~ (~n \le 10^5, m \le 2\times 10^5~). The next ~m~ lines will consist of three integers ~a~ ~b~ and ~c~, representing an undirected edge between nodes ~a~ and ~b~ with weight ~c~.

Output Format

Output a single integer, the weight of the MST of the given graph. If there is no MST, output -1.

Sample Input 1

3 4
1 2 5
1 3 6
2 3 2
2 1 3

Sample Output 1

5

Sample Explanation 1

The MST is constructed with the edges (2,1,3) and (2,3,2).