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**Task** | Statistics

Time limit: | 1.00 s | Memory limit: | 512 MB |

You are given a tree that consists of $n$ nodes.

A

The first input line contains an integer $n$: the number of nodes. The nodes are numbered $1,2,\ldots,n$.

Then there are $n-1$ lines that describe the edges. Each line contains two integers $a$ and $b$: there is an edge between nodes $a$ and $b$.

Print one integer: the maximum number of pairs.

- $1 \le n \le 5 \cdot 10^5$

- $1 \le a,b \le n$

Input:

`5`

1 2

1 3

3 4

3 5

Output:

`2`

Explanation: One possible matching is $(1,2)$ and $(3,4)$.