use std::collections::{VecDeque, HashSet};

const INF: usize = 1usize << 60;

fn bfs(start: usize, paths: &Vec<Vec<usize>>) -> Vec<usize> {
    let mut ret = vec![INF; paths.len()];
    ret[start] = 0usize;
    let mut deque = VecDeque::new();
    deque.push_back(start);
    while let Some(u) = deque.pop_front() {
        for &v in paths[u].iter() {
            if ret[v] < INF { continue; }
            ret[v] = ret[u] + 1;
            deque.push_back(v);
        }
    }
    ret
}

fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();
    let mut paths = vec![vec![]; n];
    for _ in 0..n-1 {
        let mut temp = String::new();
        std::io::stdin().read_line(&mut temp).ok();
        let temp: Vec<usize> = temp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
        let a = temp[0]-1;
        let b = temp[1]-1;
        paths[a].push(b);
        paths[b].push(a);
    }

    let idx1 = (0..n).filter(|&i| paths[i].len() == 1).nth(0).unwrap();
    let idx2 = (0..n).filter(|&i| paths[i].len() == 1).nth(1).unwrap();
    let dists1 = bfs(idx1, &paths);
    let dists2 = bfs(idx2, &paths);
    let mut dist_pattern = (0..n).filter(|&i| i != idx1 && paths[i].len() == 1).map(|i| dists1[i]).collect::<HashSet<usize>>();
    (0..n).filter(|&i| i != idx2 && paths[i].len() == 1).map(|i| dists2[i]).for_each(|v| { dist_pattern.insert(v); });
    if dist_pattern.len() == 1 && paths.iter().filter(|&v| v.len() > 2).count() <= 1 {
        println!("Yes");
    } else {
        println!("No");
    }
}