#pragma GCC target("avx2")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
#define DEBUG
#ifdef DEBUG
template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
    os << '(' << p.first << ',' << p.second << ')';
    return os;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
    os << '{';
    for(int i = 0; i < (int)v.size(); i++) {
        if(i) { os << ','; }
        os << v[i];
    }
    os << '}';
    return os;
}
void debugg() { cerr << endl; }
template <class T, class... Args>
void debugg(const T &x, const Args &... args) {
    cerr << " " << x;
    debugg(args...);
}
#define debug(...)                                                             \
    cerr << __LINE__ << " [" << #__VA_ARGS__ << "]: ", debugg(__VA_ARGS__)
#define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif
using namespace std;
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef pair<ll,ll> P;
typedef pair<int,int> pii;
typedef vector<P> vpl;
typedef tuple<ll,ll,ll> tapu;
#define rep(i,n) for(int i=0; i<(n); i++)
#define REP(i,a,b) for(int i=(a); i<(b); i++)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
const int inf = 1<<30;
const ll linf = 1LL<<62;
const int MAX = 510000;
int dy[8] = {0,1,0,-1,1,-1,-1,1};
int dx[8] = {-1,0,1,0,1,-1,1,-1};
const double pi = acos(-1);
const double eps = 1e-7;
template<typename T1,typename T2> inline bool chmin(T1 &a,T2 b){
	if(a>b){
		a = b; return true;
	}
	else return false;
}
template<typename T1,typename T2> inline bool chmax(T1 &a,T2 b){
	if(a<b){
		a = b; return true;
	}
	else return false;
}
template<typename T> inline void print(T &a){
    int sz = a.size();
    for(auto itr = a.begin(); itr != a.end(); itr++){
		cout << *itr;
        sz--;
        if(sz) cout << " ";
	}
    cout << "\n";
}
template<typename T1,typename T2> inline void print2(T1 a, T2 b){
	cout << a << " " << b << "\n";
}
template<typename T1,typename T2,typename T3> inline void print3(T1 a, T2 b, T3 c){
	cout << a << " " << b << " " << c << "\n";
}
void mark() {cout << "#" << "\n";}
ll pcount(ll x) {return __builtin_popcountll(x);}
const int mod = 1e9 + 7;
//const int mod = 998244353;

vl bfs(int s, vvl &G, int n){
    vl d(n,inf);
    d[s] = 0;
    queue<int> q;
    q.push(s);
    while(!q.empty()){
        int u = q.front(); q.pop();
        for(auto v : G[u]){
            if(chmin(d[v], d[u] + 1)) q.push(v);
        }
    }
    return d;
}

int main(){
    int n; cin >> n;
    vvl G(n);
    rep(i,n-1){
        int a,b; cin >> a >> b; a--; b--;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    bool f = true;
    rep(i,n){
        if(G[i].size() > 2) f = false;
    }
    if(f){
        cout << "Yes\n";
        return 0;
    }
    auto d0 = bfs(0,G,n);
    int t = max_element(all(d0)) - d0.begin();
    auto dt = bfs(t,G,n);
    int u = max_element(all(dt)) - dt.begin();
    int mx = dt[u];
    auto du = bfs(u,G,n);
    int pre = -1;
    int now = t;
    rep(z,mx/2){
        for(auto v : G[now]){
            if(v == pre) continue;
            if(dt[v] + du[v] == mx){
                pre = now;
                now = v;
                break;
            }
        }
    }
    vl d(n,inf);
    queue<int> q;
    q.push(now);
    d[now] = 0;
    if(mx & 1){
        cout << "No\n";
        return 0;
    }
    while(!q.empty()){
        int u = q.front(); q.pop();
        for(auto v : G[u]){
            if(chmin(d[v], d[u] + 1)) q.push(v);
        }
    }
    set<int> se;
    rep(i,n){
        if(G[i].size() == 1) se.insert(d[i]);
    }
    if(se.size() == 1) cout << "Yes\n";
    else cout << "No\n";
}