#![allow(unused_macros)]
#![allow(dead_code)]
#![allow(unused_imports)]

// # ファイル構成
// - use宣言
// - libモジュール
// - main関数
// - basicモジュール
//
// 常に使うテンプレートライブラリはbasicモジュール内にあります。
// 問題に応じて使うライブラリlibモジュール内にコピペしています。
// ライブラリのコードはこちら → https://github.com/RheoTommy/at_coder
// Twitterはこちら → https://twitter.com/RheoTommy

use std::collections::*;
use std::io::{stdout, BufWriter, Write};

use crate::basic::*;
use crate::lib::*;

pub mod lib {}

fn main() {
    let out = stdout();
    let mut writer = BufWriter::new(out.lock());
    let mut sc = Scanner::new();

    let n = sc.next_usize();
    let mut vertexes = vec![vec![]; n];
    let mut cnt = vec![0; n];
    for _ in 0..n - 1 {
        let a = sc.next_usize() - 1;
        let b = sc.next_usize() - 1;
        vertexes[a].push(b);
        vertexes[b].push(a);
        cnt[b] += 1;
        cnt[a] += 1;
    }

    let mut v = vec![];
    for i in 0..n {
        if cnt[i] == 1 {
            // writeln!(writer, "{:?}", i);
            let mut queue = VecDeque::new();
            queue.push_back((i, 0));
            let mut depth = 0;
            let mut j = 0;
            let mut seen = vec![false; n];
            seen[i] = true;
            while let Some((now, d)) = queue.pop_front() {
                // writeln!(writer, "{:?}", (now, d));
                if now != i && cnt[now] != 2 {
                    depth = d;
                    j = now;
                    break;
                }
                for &next in &vertexes[now] {
                    if !seen[next] {
                        queue.push_back((next, d + 1));
                        seen[next] = true;
                    }
                }
            }
            v.push((depth, j));
        }
    }

    // writeln!(writer, "{:?}", v);

    if v.len() == 2 || v.iter().all(|vi| *vi == v[0]) {
        writeln!(writer, "{}", "Yes").unwrap();
    } else {
        writeln!(writer, "{}", "No").unwrap();
    }
}

pub mod basic {
    pub const U_INF: u64 = (1 << 60) + (1 << 30);
    pub const I_INF: i64 = (1 << 60) + (1 << 30);

    pub struct Scanner {
        buf: std::collections::VecDeque<String>,
        reader: std::io::BufReader<std::io::Stdin>,
    }

    impl Scanner {
        pub fn new() -> Self {
            Self {
                buf: std::collections::VecDeque::new(),
                reader: std::io::BufReader::new(std::io::stdin()),
            }
        }

        fn scan_line(&mut self) {
            use std::io::BufRead;
            let mut flag = 0;
            while self.buf.is_empty() {
                let mut s = String::new();
                self.reader.read_line(&mut s).unwrap();
                let mut iter = s.split_whitespace().peekable();
                if iter.peek().is_none() {
                    if flag >= 5 {
                        panic!("There is no input!");
                    }
                    flag += 1;
                    continue;
                }

                for si in iter {
                    self.buf.push_back(si.to_string());
                }
            }
        }

        pub fn next<T: std::str::FromStr>(&mut self) -> T {
            self.scan_line();
            self.buf
                .pop_front()
                .unwrap()
                .parse()
                .unwrap_or_else(|_| panic!("Couldn't parse!"))
        }

        pub fn next_usize(&mut self) -> usize {
            self.next()
        }

        pub fn next_int(&mut self) -> i64 {
            self.next()
        }

        pub fn next_uint(&mut self) -> u64 {
            self.next()
        }

        pub fn next_chars(&mut self) -> Vec<char> {
            self.next::<String>().chars().collect()
        }

        pub fn next_string(&mut self) -> String {
            self.next()
        }

        pub fn next_char(&mut self) -> char {
            self.next()
        }

        pub fn next_float(&mut self) -> f64 {
            self.next()
        }
    }
}