fn run<'a, F: FnMut() -> &'a str, W: std::io::Write>(scan: &mut F, writer: &mut W) {
    macro_rules! scan {
        ([$t:tt; $n:expr]) => ((0..$n).map(|_| scan!($t)).collect::<Vec<_>>());
        (($($t:tt),*)) => (($(scan!($t)),*));
        (Usize1) => (scan!(usize) - 1);
        (Bytes) => (scan().as_bytes().to_vec());
        ($t:ty) => (scan().parse::<$t>().unwrap());
    }
    macro_rules! println {
        ($($arg:tt)*) => (writeln!(writer, $($arg)*).ok());
    }

    let n = scan!(usize);

    let mut graph = vec![vec![]; n];
    let mut degree = vec![0; n];
    for _ in 0..(n - 1) {
        let (a, b) = scan!((Usize1, Usize1));
        graph[a].push(b);
        graph[b].push(a);
        degree[a] += 1;
        degree[b] += 1;
    }

    let mut deque = std::collections::VecDeque::new();
    let mut dist = vec![0; n];
    for (to, degree) in degree.into_iter().enumerate() {
        if degree == 1 {
            deque.push_back(to);
            dist[to] = 1;
        }
    }

    while let Some(from) = deque.pop_front() {
        for &to in &graph[from] {
            if dist[to] == 0 {
                deque.push_back(to);
                dist[to] = dist[from] + 1;
            } else if dist[from] <= dist[to] && dist[from] + 1 != dist[to] {
                println!("No");
                return;
            }
        }
    }
    println!("Yes");
}

fn main() {
    let ref mut buf = Vec::new();
    std::io::Read::read_to_end(&mut std::io::stdin(), buf).ok();
    let mut scanner = unsafe {
        std::str::from_utf8_unchecked(buf).split_ascii_whitespace()
    };
    let ref mut scan = || scanner.next().unwrap();

    let stdout = std::io::stdout();
    let ref mut writer = std::io::BufWriter::new(stdout.lock());

    run(scan, writer);
}