#include <bits/stdc++.h>
using namespace std;
int main(){
  int N;
  cin >> N;
  vector<vector<int>> E(N);
  for (int i = 0; i < N - 1; i++){
    int a, b;
    cin >> a >> b;
    a--;
    b--;
    E[a].push_back(b);
    E[b].push_back(a);
  }
  vector<int> r;
  for (int i = 0; i < N; i++){
    if (E[i].size() >= 3){
      r.push_back(i);
    }
  }
  if (r.empty()){
    cout << "Yes" << endl;
  } else if (r.size() >= 2){
    cout << "No" << endl;
  } else {
    vector<int> d(N, -1);
    d[r[0]] = 0;
    queue<int> Q;
    Q.push(r[0]);
    while (!Q.empty()){
      int v = Q.front();
      Q.pop();
      for (int w : E[v]){
        if (d[w] == -1){
          d[w] = d[v] + 1;
          Q.push(w);
        }
      }
    }
    int L = -1;
    bool ok = true;
    for (int i = 0; i < N; i++){
      if (E[i].size() == 1){
        if (L == -1){
          L = d[i];
        } else if (L != d[i]){
          ok = false;
        }
      }
    }
    if (ok){
      cout << "Yes" << endl;
    } else {
      cout << "No" << endl;
    }
  }
}