#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); i++)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;

int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);

  int N; cin >> N;
  vector<unordered_set<int>> graph(N);
  vector<unordered_set<int>> ograph(N);
  rep(i, 0, N-1) {
    int a, b; cin >> a >> b;
    a--; b--;
    graph[a].insert(b);
    graph[b].insert(a);
    ograph[a].insert(b);
    ograph[b].insert(a);
  }
  if (N == 1) {
    cout << "YES" << endl;
    return 0;
  }
  vi unblocked_leaves;
  vector<set<pii>> blocked_leaves_at(N);
  vi population(N, 1);
  rep(i, 0, N) {
    if (sz(graph[i]) == 1) {
      unblocked_leaves.push_back(i);
    }
  }
  while (sz(unblocked_leaves) > 0) {
    int l = unblocked_leaves[sz(unblocked_leaves)-1];
    unblocked_leaves.pop_back();
    //cerr << "moving " << l << endl;
    int par = *graph[l].begin();
    population[par] += population[l];
    population[l] = 0;
    graph[par].erase(l);
    if (population[par] == N) {
      cout << "YES" << endl;
      return 0;
    }
    if (sz(graph[par]) == 1) {
      if (population[*graph[par].begin()] >= population[par]) {
        unblocked_leaves.push_back(par);
      } else {
        blocked_leaves_at[*graph[par].begin()].insert(make_pair(population[par],par));
      }
    }
    while (sz(blocked_leaves_at[par]) > 0 && blocked_leaves_at[par].begin()->first <= population[par]) {
      auto [npop, neigh] = *blocked_leaves_at[par].begin();
      //assert(npop == population[neigh]);
      //assert(sz(graph[neigh]) == 1);
      blocked_leaves_at[par].erase(make_pair(npop, neigh));
      unblocked_leaves.push_back(neigh);
    }
  }
  /*
  rep(i, 0, N) {
    int numneigh = 0;
    int maxneighpop = 0;
    for(int n : ograph[i]) {
      if (population[n] > 0) numneigh++;
      maxneighpop = max(maxneighpop, population[n]);
    }
    assert((population[i] == 0) + (numneigh > 1) + (maxneighpop < population[i]) == 1);
  }
  */
  cout << "NO" << endl;
}