#![allow(unused_imports)]
use std::cmp::*;
use std::collections::*;
use std::io::Write;
use std::ops::Bound::*;

#[allow(unused_macros)]
macro_rules! debug {
    ($($e:expr),*) => {
        #[cfg(debug_assertions)]
        $({
            let (e, mut err) = (stringify!($e), std::io::stderr());
            writeln!(err, "{} = {:?}", e, $e).unwrap()
        })*
    };
}

fn main() {
    let n = read::<usize>();
    let mut edges = vec![vec![]; n];
    for i in 0..n - 1 {
        let v = read_vec::<usize>();
        let (a, b) = (v[0] - 1, v[1] - 1);
        edges[a].push((b, 1));
        edges[b].push((a, 1));
    }

    let mut leafs = vec![];
    for i in 0..n {
        if edges[i].len() == 1 {
            leafs.push(i);
        }
    }

    let mut cores = vec![];
    for i in 0..n {
        if edges[i].len() >= 3 {
            cores.push(i);
        }
    }

    if cores.len() >= 2 {
        println!("No");
        return;
    }

    if cores.len() == 0 {
        println!("Yes");
        return;
    }

    let d = solve(&edges, cores[0]);
    if leafs.iter().all(|&li| d[leafs[0]] == d[li]) {
        println!("Yes");
    } else {
        println!("No");
    }
}

fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}

type Cost = i64;
const INF: Cost = 100000_00000_00000;

fn solve(edges: &Vec<Vec<(usize, Cost)>>, start_idx: usize) -> Vec<Cost> {
    let num_apexes = edges.len();
    let mut d = vec![INF; num_apexes];
    d[start_idx] = 0;
    let mut que = std::collections::BinaryHeap::new();
    que.push((std::cmp::Reverse(0), start_idx));

    while let Some((u, v)) = que.pop() {
        if d[v] < u.0 {
            continue;
        }
        for e in &edges[v] {
            if d[v] != INF && d[e.0] > d[v] + e.1 {
                d[e.0] = d[v] + e.1;
                que.push((std::cmp::Reverse(d[e.0]), e.0));
            }
        }
    }
    d
}