Given an undirected, weighted graph of n vertices and m edges.
If your path from u to v consists of k edges weigh w1,w2,...,wk, then the final weight of the path is calculated as follow:
w1+w2+...+wk−max(w1,w2,...,wk)
Find the weight of the shortest path from 1 to n.
### Input
- The first line contains 2 integers n,m.
- The next m lines, each line contains 3 integers u,v,w, there is an edge of weight w connecting u,v.
### Output
- Print the weight of the shortest path from 1 to n, or print −1 if no path exists.
### Constraints
- 1≤n,m≤2×105.
- 1≤u,v≤n.
- 1≤w≤109.
### Example
Input:
33121232133
Output:
0