#include<bits/stdc++.h>
using namespace std;
//#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
#define vec vector<ll>
#define mat vector<vector<ll> >
#define fi first
#define se second
#define double long double
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
//typedef long double ld;
typedef complex<double> Complex;
const ll INF=1e9+7;
const ll MOD=998244353;
const ll inf=INF;
const ll mod=INF;
const ll MAX=200010;





signed main(){
    ll n;cin>>n;
    vector<vector<ll> >G(n);
    vector<ll>d(n);
    rep(i,n-1){
        ll a,b;cin>>a>>b;
        a--;b--;
        G[a].pb(b);
        G[b].pb(a);
        d[a]++;
        d[b]++;
    }
    bool f=1;
    ll m=-1;
    ll ma=0;
    rep(i,n){
        if(ma<d[i]){
            m=i;
            ma=d[i];
        }
    }
    ll ma2=0;
    rep(i,n){
        if(m!=i){
            ma2=max(ma2,d[i]);
        }
    }
    if(ma2>2)f=0;
    queue<ll>q;
    vector<ll>dist(n,-1);
    dist[m]=0;
    q.push(m);
    while(!q.empty()){
        ll k=q.front();
        q.pop();
        for(auto e:G[k]){
            if(dist[e]>=0)continue;
            dist[e]=dist[k]+1;
            q.push(e);
        }
    }
    ll s=-1;
    ll cnt=0;
    rep(i,n){
        if(d[i]==1){
            cnt++;
            if(s==-1)s=dist[i];
            else if(s!=dist[i])f=0;
        }
    }
    if(cnt==2)f=1;
    cout<<(f?"Yes":"No")<<endl;
}