#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(200000,-1);
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 main(){
  
  int n;
  cin >> n;
  vector<int> deg(n);
  vector<vector<int>> v(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;
  int root = 0;
  rep(i,n)if(deg[i] >= 3)cnt++,root = i;
  d[root] = 0;
  dfs(v,root);
  int mn = MOD,mx = 0;
  rep(i,n)if(i != root && deg[i] == 1)mn = min(mn,d[i]),mx = max(mx,d[i]);
  if(cnt == 0)mn = mx;
  cout << (mn == mx && cnt <= 1 ? "Yes\n" : "No\n");
  


  return 0;
}