#![allow(unused)]

use kyoproio::*;
use std::{
    io::{self, prelude::*},
    collections::*,
    iter,
    mem::{replace, swap},
};

fn main() -> io::Result<()> {
    std::thread::Builder::new()
        .stack_size(50 * 1024 * 1024)
        .spawn(solve)?
        .join()
        .unwrap();
    Ok(())
}

fn solve() {
    let stdin = io::stdin();
    let mut kin = KInput::new(stdin.lock());
    let stdout = io::stdout();
    let mut out = io::BufWriter::new(stdout.lock());
    macro_rules! output {
        ($($args:expr),+) => { write!(&mut out, $($args),+) };
    }
    macro_rules! outputln {
        ($($args:expr),+) => { output!($($args),+); outputln!() };
        () => { output!("\n"); if cfg!(debug_assertions) { out.flush(); } }
    }

    let n: usize = kin.input();
    let mut g: Vec<_> = iter::repeat_with(Vec::new).take(n + 1).collect();
    for _ in 0..n - 1 {
        let (u, v): (usize, usize) = kin.input();
        g[u].push(v);
        g[v].push(u);
    }
    let mut dp = vec![[!0, !0]; n + 1];
    let ans = dfs(&g, 0, 1, 0, &mut dp).max(dfs(&g, 1, 1, 0, &mut dp));
    outputln!("{}", ans);
}

pub fn dfs(g: &[Vec<usize>], col: usize, u: usize, p: usize, dp: &mut [[usize; 2]]) -> usize {
    if dp[u][col] < !0 {
        return dp[u][col];
    }
    dp[u][col] = col;
    for &v in g[u].iter().filter(|&&v| v != p) {
        dp[u][col] += if col == 0 {
            dfs(g, 0, v, u, dp).max(dfs(g, 1, v, u, dp))
        } else {
            dfs(g, 0, v, u, dp)
        };
    }
    dp[u][col]
}

// -----------------------------------------------------------------------------
pub mod kyoproio {
    #![warn(unused)]
    use std::io::prelude::*;
    pub trait Input: Sized {
        fn str(&mut self) -> &str;
        fn bytes(&mut self) -> &[u8] {
            self.str().as_ref()
        }
        fn input<T: InputParse>(&mut self) -> T {
            self.input_fallible().expect("input error")
        }
        fn input_fallible<T: InputParse>(&mut self) -> Result<T> {
            T::input(self)
        }
        fn iter<T: InputParse>(&mut self) -> Iter<T, Self> {
            Iter {
                input: self,
                _t: std::marker::PhantomData,
            }
        }
        fn seq<T: InputParse, B: std::iter::FromIterator<T>>(&mut self, n: usize) -> B {
            self.iter().take(n).collect()
        }
    }
    pub struct KInput<R> {
        src: R,
        buf: String,
        pos: usize,
    }
    impl<R: BufRead> KInput<R> {
        pub fn new(src: R) -> Self {
            Self {
                src,
                buf: String::with_capacity(1024),
                pos: 0,
            }
        }
    }
    impl<R: BufRead> Input for KInput<R> {
        fn str(&mut self) -> &str {
            loop {
                if self.pos >= self.buf.len() {
                    self.pos = 0;
                    self.buf.clear();
                    if self.src.read_line(&mut self.buf).expect("io error") == 0 {
                        return &self.buf;
                    }
                }
                let range = self.pos
                    ..self.buf[self.pos..]
                        .find(|c: char| c.is_ascii_whitespace())
                        .map(|i| i + self.pos)
                        .unwrap_or_else(|| self.buf.len());
                self.pos = range.end + 1;
                if range.end > range.start {
                    return &self.buf[range];
                }
            }
        }
    }
    pub struct Iter<'a, T, I> {
        input: &'a mut I,
        _t: std::marker::PhantomData<T>,
    }
    impl<'a, T: InputParse, I: Input> Iterator for Iter<'a, T, I> {
        type Item = T;
        fn next(&mut self) -> Option<Self::Item> {
            Some(self.input.input())
        }
    }
    type Result<T> = std::result::Result<T, Box<dyn std::error::Error + 'static>>;
    pub trait InputParse: Sized {
        fn input<I: Input>(input: &mut I) -> Result<Self>;
    }
    macro_rules! input_from_str_impls {
        { $($T:ty)* } => {
            $(impl InputParse for $T {
                fn input<I: Input>(input: &mut I) -> Result<Self> {
                    input.str().parse::<$T>().map_err(|e| e.into())
                }
            })*
        };
    }
    input_from_str_impls! {
        String char bool f32 f64
        isize i8 i16 i32 i64 i128
        usize u8 u16 u32 u64 u128
    }
    macro_rules! input_tuple_impls {
        ($H:ident, $($T:ident),+) => {
            impl<$H: InputParse, $($T: InputParse),+> InputParse for ($H, $($T),+) {
                fn input<I: Input>(input: &mut I) -> Result<Self> {
                    Ok(($H::input(input)?, $($T::input(input)?),+))
                }
            }
            input_tuple_impls!($($T),+);
        };
        ($H:ident) => {};
    }
    input_tuple_impls!(A, B, C, D, E, F, G);
    /*
    impl<T: InputParse, const N: usize> InputParse for [T; N] {
        fn input<I: Input>(input: &mut I) -> Result<Self> {
            let mut a = std::mem::MaybeUninit::<[T; N]>::uninit();
            for i in 0..N {
                match T::input(input) {
                    Ok(v) => unsafe { std::ptr::write(&mut (*a.as_mut_ptr())[i], v) },
                    Err(e) => unsafe {
                        std::ptr::drop_in_place(&mut (*a.as_mut_ptr())[..i]);
                        return Err(e);
                    },
                }
            }
            Ok(unsafe { a.assume_init() })
        }
    }
    */
}