import java.io.PrintWriter
import java.util.*
import kotlin.math.*

fun PrintWriter.solve() {
    val n = nextInt()
    val adj = Array(n) { mutableSetOf<Int>() }
    for (i in 0 until n - 1) {
        val v1 = nextInt() - 1
        val v2 = nextInt() - 1
        adj[v1].add(v2)
        adj[v2].add(v1)
    }
    val lst = mutableListOf<Int>()
    for (i in 0 until n) {
        if (adj[i].count() >= 3) {
            lst.add(i)
        }
    }
    if (lst.count() >= 2) {
        println("No")
    } else if (lst.count() == 0) {
        println("Yes")
    } else {
        val lens = mutableSetOf<Int>()
        val que: Queue<Triple<Int, Int, Int>> = ArrayDeque()
        que.add(Triple(lst[0], -1, 0))
        while (que.count() > 0) {
            val (v, p, d) = que.poll()
            var isleaf = true
            for (w in adj[v]) {
                if (w != p) {
                    isleaf = false
                    que.add(Triple(w, v, d + 1))
                }
            }
            if (isleaf) {
                lens.add(d)
            }
        }
        println(if (lens.count() == 1) "Yes" else "No")
    }
}

fun main() {
    val writer = PrintWriter(System.out, false)
    writer.solve()
    writer.flush()
}

// region Scanner
private var st = StringTokenizer("")
private val br = System.`in`.bufferedReader()

fun next(): String {
    while (!st.hasMoreTokens()) st = StringTokenizer(br.readLine())
    return st.nextToken()
}

fun nextInt() = next().toInt()
fun nextLong() = next().toLong()
fun nextLine() = br.readLine()
fun nextDouble() = next().toDouble()
// endregion