#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename  T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

std::vector<int> centroid(const std::vector<std::vector<int>> &graph) {
  int n = graph.size();
  std::vector<int> subtree(n, 1), res;
  std::function<void(int, int)> dfs = [&graph, n, &subtree, &res, &dfs](int par, int ver) {
    bool is_centroid = true;
    for (int e : graph[ver]) {
      if (e != par) {
        dfs(ver, e);
        subtree[ver] += subtree[e];
        is_centroid &= subtree[e] <= n / 2;
      }
    }
    if (is_centroid && (n - subtree[ver]) <= n / 2) res.emplace_back(ver);
  };
  dfs(-1, 0);
  std::sort(res.begin(), res.end());
  return res;
}

int main() {
  int n; cin >> n;
  vector<vector<int>> graph(n);
  REP(_, n - 1) {
    int a, b; cin >> a >> b; --a; --b;
    graph[a].emplace_back(b);
    graph[b].emplace_back(a);
  }
  vector<int> cen = centroid(graph);
  REP(i, n) {
    if (count(ALL(cen), i) == 0 && graph[i].size() > 2) {
      cout << "No\n";
      return 0;
    }
  }
  auto f = [&](auto &&f, int par, int ver) -> int {
    if (graph[ver].size() == 1) return 0;
    return f(f, ver, graph[ver][graph[ver][0] == par ? 1 : 0]) + 1;
  };
  vector<int> dist;
  if (cen.size() == 1) {
    for (int e : graph[cen[0]]) dist.emplace_back(f(f, cen[0], e));
  } else {
    for (int e : graph[cen[0]]) {
      if (e != cen[1]) dist.emplace_back(f(f, cen[0], e));
    }
    for (int e : graph[cen[1]]) {
      if (e != cen[0]) dist.emplace_back(f(f, cen[1], e));
    }
  }
  sort(ALL(dist));
  cout << (dist.empty() || dist.front() == dist.back() ? "Yes\n" : "No\n");
  return 0;
}