Longest path in a tree

Input

The first line contains the number of vertices in the tree $n$ (2 \le n \le 10^5).

Each of the following n - 1 lines describes an edge of the tree. Each line contains three integers $u$, $v$, and $w$, where $u$ and $v$ are the numbers of the vertices connected by the edge (vertices are numbered from $1$ to $n$), and $w$ (1 \le w \le 10^5) is the weight of the edge.

Output

Print the length of the longest path in the tree.

Examples