#include"bits/stdc++.h"
using namespace std;
#define ALL(x) begin(x),end(x)
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define mod 1000000007
using ll=long long;
const int INF=1000000000;
const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0},dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

struct IOSetup{
    IOSetup(){
        cin.tie(0);
        ios::sync_with_stdio(0);
        cout<<fixed<<setprecision(12);
    }
} iosetup;
 
template<typename T>
ostream &operator<<(ostream &os,const vector<T>&v){
    for(int i=0;i<(int)v.size();i++) os<<v[i]<<(i+1==(int)v.size()?"":" ");
    return os;
}
template<typename T>
istream &operator>>(istream &is,vector<T>&v){
    for(T &x:v)is>>x;
    return is;
}

// graph template
// ref : https://ei1333.github.io/library/graph/graph-template.cpp
template<typename T=int>
struct Edge{
    int from,to;
    T w;
    int idx;
    Edge()=default;
    Edge(int from,int to,T w=1,int idx=-1):from(from),to(to),w(w),idx(idx){}
    operator int() const{return to;}
};

template<typename T=int>
struct Graph{
    vector<vector<Edge<T>>> g;
    int V,E;
    Graph()=default;
    Graph(int n):g(n),V(n),E(0){}

    int size(){
        return (int)g.size();
    }
    void resize(int k){
        g.resize(k);
        V=k;
    }
    inline const vector<Edge<T>> &operator[](int k)const{
        return (g.at(k));
    }
    inline vector<Edge<T>> &operator[](int k){
        return (g.at(k));
    }
    void add_directed_edge(int from,int to,T cost=1){
        g[from].emplace_back(from,to,cost,E++);
    }
    void add_edge(int from,int to,T cost=1){
        g[from].emplace_back(from,to,cost,E);
        g[to].emplace_back(to,from,cost,E++);
    }
    void read(int m,int pad=-1,bool weighted=false,bool directed=false){
        for(int i=0;i<m;i++){
            int u,v;cin>>u>>v;
            u+=pad,v+=pad;
            T w=T(1);
            if(weighted) cin>>w;
            if(directed) add_directed_edge(u,v,w);
            else         add_edge(u,v,w);
        }
    }
};

template<typename T>
vector<int> TreeCenter(Graph<T> G){
    auto BFS=[&](Graph<T> &g,int st,vector<int> &dis,bool memo_parent=false){
        vector<int> par;
        if(memo_parent) par.assign(g.size(),-1);
        dis.assign(g.size(),-1);
        dis[st]=0;
        queue<int> que;
        que.push(st);
        while(!que.empty()){
            int cur=que.front();que.pop();
            for(auto &to:g[cur]){
                if(dis[to]>=0) continue;
                dis[to]=dis[cur]+1;
                if(memo_parent) par[to]=cur;
                que.push(to);
            }
        }
        return par;
    };
    vector<int> d;
    BFS(G,0,d);
    int u=max_element(begin(d),end(d))-begin(d);
    
    auto par=BFS(G,u,d,true);
    int v=max_element(begin(d),end(d))-begin(d);
    int diameter=d[v];
    for(int i=0;i<diameter/2;i++) v=par[v];
    vector<int> ret;
    ret.push_back(v);
    if(diameter%2) ret.push_back(par[v]);
    return ret;
}

template<typename T>
struct Dijkstra{
    const T inf;
    Graph<T> g;
    vector<T> d;
    vector<int> prev,eid;
    
    Dijkstra(Graph<T> g):inf(numeric_limits<T>::max()/4),g(g){}

    vector<T> build(int st){
        d.assign(g.V,inf);
        prev.assign(g.V,-1);
        eid.assign(g.V,-1);
        d[st]=0;
        priority_queue<pair<T,int>,vector<pair<T,int>>,greater<pair<T,int>>> que;
        que.emplace(d[st],st);
        while(!que.empty()){
            auto p=que.top();que.pop();
            int cur=p.second;
            if(d[cur]<p.first) continue;
            for(auto &e:g[cur]){
                if(d[e]>d[cur]+e.w){
                    d[e]=d[cur]+e.w;
                    prev[e]=cur;
                    que.emplace(d[e],e);
                }
            }
        }
        return d;
    }

    // vertex = false :-> edge idx
    vector<int> get_path(int gl,bool vertex=true){
        vector<int> ret;
        if(d[gl]==inf) return ret;
        for(;gl!=-1;gl=prev[gl]){
            ret.push_back(vertex?gl:eid[gl]);
        }
        reverse(ret.begin(),ret.end());
        return ret;
    }
};

signed main(){
    int N;cin>>N;
    Graph<int> G(N);
    G.read(N-1);

    int cnt=0;
    rep(i,N)if(G[i].size()==1) cnt++;
    if(cnt<=2){
        cout<<"Yes"<<endl;
        return 0;
    }

    auto center=TreeCenter(G);

    for(auto &c:center){
        Dijkstra<int> dij(G);
        auto d=dij.build(c);
        set<int> st;
        rep(i,N){
            if(G[i].size()==1) st.insert(d[i]);
        }
        if(st.size()==1){
            cout<<"Yes"<<endl;
            return 0;
        }
    }
    cout<<"No"<<endl;
    return 0;
}