#include<bits/stdc++.h>
// #include<atcoder/all>
// #include<boost/multiprecision/cpp_int.hpp>

using namespace std;
// using namespace atcoder;
// using bint = boost::multiprecision::cpp_int;
using ll = long long;
using ull = unsigned long long;
using P = pair<int,int>;
#define rep(i,n) for(ll i = 0;i < (ll)n;i++)
#define ALL(x) (x).begin(),(x).end()
#define MOD 1000000007


vector<int> d;
void dfs(vector<vector<int>> &v,int ov){
  for(auto nv : v[ov]){
    if(d[nv] != -1)continue;
    d[nv] = d[ov] + 1;
    dfs(v,nv);
  }
}

int n;
vector<int> deg(200000);
vector<vector<int>> v(200000);

bool solve(int root){
  d.assign(n,-1);
  d[root] = 0;
  dfs(v,root);
  vector<int> w;
  rep(i,n)if(deg[i] == 1 && i != root)w.push_back(d[i]);
  sort(ALL(w));
  return w[0] == w.back();
}

int main(){
  
  cin >> n;
  rep(i,n-1){
    int a,b;cin >> a >> b;
    a--;b--;
    deg[a]++;deg[b]++;
    v[a].push_back(b);
    v[b].push_back(a);
  }
  int cnt = 0;
  rep(i,n){
    if(deg[i] == 1){
      if(!solve(i)){
        cout << "No\n";
        return 0;
      }else cnt++;
    }
    if(cnt == 2)break;
  }
  cout << "Yes\n";
  


  return 0;
}