#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#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(v) begin(v),end(v)
#define rall(v) rbegin(v),rend(v)
#define fi first
#define se second
#define re0 return 0
template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
constexpr ll inf = 2e9;
constexpr ll llinf = 9e18;
//constexpr ll MOD = 998244353;
constexpr ll MOD = 1000000007;
const double pai=acos(-1);

int main() {
    //cout<<fixed<<setprecision(15);
    int n;cin>>n;
    vector<vector<int>> g(n);
    rep(i,n-1){
        int a,b;cin>>a>>b;
        a--;b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    int tmp=0,id;
    rep(i,n){
        int a=g[i].size();
        if(a>tmp){
            tmp=a;
            id=i;
        }
    }
    if(tmp==1||tmp==2){
        cout<<"Yes"<<endl;
        re0;
    }
    //cout<<id<<endl;
    vector<int> vec(n),vec1(n);
    vector<int> d(n,-1);
    queue<int> que;
    d[id]=0;
    que.push(id);
    while(!que.empty()){
        int v=que.front();que.pop();
        for(auto u:g[v]){
            if(d[u]!=-1)continue;
            d[u]=d[v]+1;
            que.push(u);
            if(g[u].size()==1)vec[u]=1,vec1[v]++;
        }
    }
    //rep(i,n)cout<<d[i]<<endl;
    set<int> st;
    rep(i,n){
        if(vec[i])st.insert(d[i]);
    }
    bool ok=true;
    if(st.size()!=1)ok=false;
    rep(i,n){
        for(auto u:g[i]){
            if(vec[i]&&vec1[u]>1&&u!=id)ok=false;
        }
    }
    if(ok)cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
}