#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <utility>
#include <cmath>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <tuple>
#include <numeric>
#include <functional>
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
typedef pair<ll, ll> P;
#define rep(i, n) for(ll i = 0; i < n; i++)
#define exrep(i, a, b) for(ll i = a; i <= b; i++)
#define out(x) cout << x << endl
#define exout(x) printf("%.10f\n", x)
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define pb push_back
#define re0 return 0
const ll mod = 1000000007;
const ll INF = 1e16;

struct Edge {
    ll to, cost;
    Edge(ll to, ll cost): to(to), cost(cost) {}
};

int main() {
    ll n;
    cin >> n;
    
    vector<vector<Edge>> G(n);
    vl deg(n);
    rep(i, n-1) {
        ll a, b;
        cin >> a >> b;
        a--;  b--;
        G[a].emplace_back(b, 1);
        G[b].emplace_back(a, 1);
        deg[a]++;  deg[b]++;
    }
    
    vl dist(n, -1);  // dist[v] : 頂点vの根からの距離
    queue<ll> Q;
    const ll root = 0;
    dist[root] = 0;
    Q.push(root);
    while(!Q.empty()) {
        ll v = Q.front();  Q.pop();
        for(Edge e : G[v]) {
            if(dist[e.to] == -1) {
                dist[e.to] = dist[v] + e.cost;
                Q.push(e.to);
            }
        }
    }
    
    bool ok = true;
    ll x = -1;
    rep(v, n) {
        if(v != root && deg[v] == 1) {
            if(x == -1) {
                x = dist[v];
            }
            else if(x != dist[v]) {
                ok = false;
            }
        }
    }

    if(ok) {
        out("Yes");
    }
    else {
        out("No");
    }
    
    re0;
}