#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <cmath>
#include <map>
#include <queue>
#include <iomanip>
#include <set>
#include <tuple>
#define mkp make_pair
#define mkt make_tuple
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define all(v) v.begin(),v.end()
using namespace std;
typedef long long ll;
const ll MOD=1e9+7;
template<class T> void chmin(T &a,const T &b){if(a>b) a=b;}
template<class T> void chmax(T &a,const T &b){if(a<b) a=b;}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  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);
  }

  vector<int> deg(N,0);
  rep(i,N) deg[i]=g[i].size();

  int root=-1;
  rep(i,N) if(deg[i]>=3){
    if(root==-1) root=i;
    else{
      cout<<"No"<<endl;
      return 0;
    }
  }
  if(root==-1){
    cout<<"Yes"<<endl;
    return 0;
  }

  vector<int> dep(N,MOD);
  queue<int> Q;
  Q.push(root);
  dep[root]=0;
  while(!Q.empty()){
    int now=Q.front();
    Q.pop();

    for(auto nex:g[now]){
      if(dep[nex]==MOD){
        dep[nex]=dep[now]+1;
        Q.push(nex);
      }
    }
  }

  int value=-1;
  rep(i,N) if(deg[i]==1){
    if(value==-1) value=dep[i];
    else if(dep[i]!=value){
      cout<<"No"<<endl;
      return 0;
    }
  }
  cout<<"Yes"<<endl;

  return 0;
}