Problem9253--ABC293 —— Ex - Optimal Path Decomposition

9253: ABC293 —— Ex - Optimal Path Decomposition

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Time Limit : 1.000 sec  Memory Limit : 512 MiB

Description

### Problem Statement

You are given a tree with $N$ vertices numbered $1$ through $N$. The $i$-th edge connects vertex $A_i$ and vertex $B_i$.

Find the minimum integer $K$ such that you can paint each vertex in a color so that the following two conditions are satisfied. You may use any number of colors.

-   For each color, the set of vertices painted in the color is connected and forms a simple path.
-   For all simple paths on the tree, there are at most $K$ distinct colors of the vertices in the path.

Input

### Input

The input is given from Standard Input in the following format:

```
$N$
$A_1$ $B_1$
$\vdots$
$A_{N-1}$ $B_{N-1}$
```

Output

### Output

Print the answer.

Constraints

### Constraints

-   $1 \leq N \leq 2 \times 10^5$
-   $1 \leq A_i, B_i \leq N$
-   The given graph is a tree.
-   All values in the input are integers.

Sample 1 Input

7
3 4
1 5
4 5
1 2
7 4
1 6

Sample 1 Output

3
If K=3, the conditions can be satisfied by painting vertices 1,2,3,4, and 5 in color 1, vertex 6 in color 2, and vertex 7 in color 3. If K≤2, there is no way to paint the vertices to satisfy the conditions, so the answer is 3.

Sample 2 Input

6
3 5
6 4
6 3
4 2
1 5

Sample 2 Output

1

Sample 3 Input

9
1 3
9 5
8 7
2 1
5 2
5 8
4 8
6 1

Sample 3 Output

3

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