#[allow(unused_macros)]
macro_rules! input {
	(source = $s:expr, $($r:tt)*) => {
		let mut iter = $s.split_whitespace();
		input_inner!{iter, $($r)*}
	};
	($($r:tt)*) => {
		let s = {
			use std::io::Read;
			let mut s = String::new();
			std::io::stdin().read_to_string(&mut s).unwrap();
			s
		};
		let mut iter = s.split_whitespace();
		input_inner!{iter, $($r)*}
	};
}
#[allow(unused_macros)]
macro_rules! input_inner {
	($iter:expr) => {};
	($iter:expr, ) => {};

	($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
		let $var = read_value!($iter, $t);
		input_inner!{$iter $($r)*}
	};
}
#[allow(unused_macros)]
macro_rules! read_value {
	($iter:expr, ( $($t:tt),* )) => {
		( $(read_value!($iter, $t)),* )
	};

	($iter:expr, [ $t:tt ; $len:expr ]) => {
		(0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
	};

	($iter:expr, chars) => {
		read_value!($iter, String).chars().collect::<Vec<char>>()
	};

	($iter:expr, usize1) => {
		read_value!($iter, usize) - 1
	};

	($iter:expr, $t:ty) => {
		$iter.next().unwrap().parse::<$t>().expect("Parse error")
	};
}

fn dfs(s: usize, graph:&Vec<Vec<usize>>, used: &mut Vec<bool>, d: &mut Vec<i32>, cd: i32) {
	used[s] = true;
	d[s] = cd;
	for g in &graph[s] {
		if !used[*g] {
			dfs(*g, graph, used, d, cd+1);
		}
	}
}

fn main() {
	input! {
		n: usize,
		edges: [(usize1, usize1); (n-1)],
	}
	let mut graph: Vec<Vec<usize>> = vec![vec![]; n];
	let mut used: Vec<bool> = vec![false; n];
	let mut d: Vec<i32> = vec![0; n];
	let mut deg: Vec<usize> = vec![0; n];
	let mut dis = vec![];
	for (s, v) in &edges {
		deg[*s] += 1;
		deg[*v] += 1;
		graph[*s].push(*v);
		graph[*v].push(*s);
	}
	dfs(0, &graph, &mut used, &mut d, 0);
	for i in 0..n {
		if deg[i] == 1 {
			dis.push(d[i]);
		}
	}
	dis.sort_by(|a, b| b.cmp(a));
	let ans_ex = dis[0]+dis[1]+1;
	let ans = n as i32-ans_ex;
	println!("{}", ans);
	// println!("{:?}", d);
}