#include<bits/stdc++.h>

using namespace std;
using Graph=vector<vector<int>>;

void rep(int v,int pv,int d,vector<int> &res,Graph &g){
  res[v]=d;
  for(auto &nx : g[v]){
    if(nx==pv){continue;}
    rep(nx,v,d+1,res,g);
  }
}

int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  Graph g(n);
  for(int i=1;i<n;i++){
    int u,v;
    cin >> u >> v;
    u--;v--;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  int bas=-1;
  for(int i=0;i<n;i++){
    if(g[i].size()>2){
      if(bas==-1){bas=i;}
      else{cout << "No\n";return 0;}
    }
  }
  if(bas==-1){cout << "Yes\n";return 0;}
  vector<int> res(n);
  rep(bas,-1,0,res,g);
  int ld=-1;
  for(int i=0;i<n;i++){
    if(g[i].size()==1){
      if(ld==-1){ld=res[i];}
      else if(ld!=res[i]){cout << "No\n";return 0;}
    }
  }
  cout << "Yes\n";
  return 0;
}