use std::collections::HashSet;


fn dfs(cur: usize, prev: usize, paths: &Vec<Vec<(usize, usize)>>, depth: &mut usize, dists: &mut HashSet<usize>) {
    let mut is_leaf = true;
    for &(v, _) in paths[cur].iter() {
        if v == prev { continue; }
        *depth += 1;
        dfs(v, cur, paths, depth, dists);
        *depth -= 1;
        is_leaf = false;
    }
    if is_leaf {
        dists.insert(*depth);
    }
}

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 ab = String::new();
        std::io::stdin().read_line(&mut ab).ok();
        let ab: Vec<usize> = ab.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
        let a = ab[0]-1;
        let b = ab[1]-1;
        paths[a].push((b, 1));
        paths[b].push((a, 1));
    }

    let size = paths.iter().filter(|&v| v.len() >= 3).count();
    if size > 2 {
        println!("No");
    } else if size == 0 {
        println!("Yes");
    } else {
        let idx = paths.iter().enumerate().filter(|&(i, v)| v.len() >= 3).nth(0).unwrap().0;
        let mut leaf_dists = HashSet::new();
        let mut depth = 0usize;
        dfs(idx, idx, &paths, &mut depth, &mut leaf_dists);
        if leaf_dists.len() == 1 {
            println!("Yes");
        } else {
            println!("No");
        }
    }
}