#include <iostream>
#include <iomanip>
#include <cstdio>
#include <queue>
#include <cstring>
#include <vector>
#include <map>
#include <algorithm>
#include <cctype>
#include <cmath>
#include <bitset>
#include <set>
#include <deque>
#include <stack>
#include <atcoder/all>

using namespace std;

#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)
#define FOR(i,k,n) for(int i=(k);i<(int)(n);i++)
#define all(i,n) (i),(i+n)

int dx4[4]={1,0,-1,0};
int dy4[4]={0,-1,0,1};
int dx8[8]={1,0,-1,1,-1,1,0,-1};
int dy8[8]={1,1,1,0,0,-1,-1,-1};

typedef pair<int, int> P;
typedef pair<string, int> SP;
typedef long long ll;
typedef pair<ll, ll> PLL;

const int INF = 1e9;
const ll LLINF = 1e18;
const int MAX_V = 1e6+1;
// const ll mod = 1e9 + 7;
//  cout << fixed << setprecision(10)
// --------------------------------------
int n;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> n;
  vector<int> g[n];

  int a, b;
  REP(i, n - 1) {
    cin >> a >> b;
    a--; b--;
    g[a].push_back(b);
    g[b].push_back(a);
  }

  int tc = 0, s;
  REP(i, n) {
    if(g[i].size() > 2) {
      tc++;
      s = i;
    }
  }

  if(tc == 0) {
    cout << "Yes" << endl;
    return 0;
  } else if(tc > 1) {
    cout << "No" << endl;
    return 0;
  }

  vector<int> onev;
  REP(i, n) {
    if(g[i].size() == 1) onev.push_back(i);
  }

  vector<int> d(n, -1);
  queue<P> que;
  que.push(P(s, 0));
  while(!que.empty()) {
    auto [ind, dis]  = que.front(); que.pop();
    d[ind] = dis;

    for(auto x: g[ind]) {
      if(d[x] == -1) {
        que.push(P(x, dis + 1));
      }
    }
  }

  bool f = true;
  int t = -1;
  REP(i, n) {
    if(g[i].size() == 1) {
      if(t != -1 && d[i] != t) {
        f = false;
      } else {
        t = d[i];
      }
    }
  }

  cout << (f ? "Yes" : "No") << endl;
}