#include <bits/stdc++.h>

using namespace std;

#define debug(x) cerr << #x << ": " << x << endl
#define debugArray(x, n)                           \
  for (long long hoge = 0; (hoge) < (n); ++(hoge)) \
  cerr << #x << "[" << hoge << "]: " << x[hoge] << endl

template <typename T, typename E>
struct Tree_DP {
  struct Edge {
    int to;
    E data;
    T dp, ndp;
  };
  using F = function<T(T, T)>;
  using G1 = function<T(T, E)>;
  using G2 = function<T(T, int)>;

 private:
  vector<vector<Edge>> graph;
  vector<T> subdp, dp;
  const T init;
  const F f;
  const G1 g1;
  const G2 g2;

 private:
  void dfs_sub(int idx, int par) {
    for (auto &e : graph[idx]) {
      if (e.to == par) continue;
      dfs_sub(e.to, idx);
      subdp[idx] = f(subdp[idx], g1(subdp[e.to], e.data));
    }
    subdp[idx] = g2(subdp[idx], idx);
  }

  void dfs_all(int idx, int par, const T &top) {
    T buff{init};
    for (int i = 0; i < (int)graph[idx].size(); i++) {
      auto &e = graph[idx][i];
      e.ndp = buff;
      e.dp = g1(par == e.to ? top : subdp[e.to], e.data);
      buff = f(buff, e.dp);
    }
    dp[idx] = g2(buff, idx);
    buff = init;
    for (int i = (int)graph[idx].size() - 1; i >= 0; i--) {
      auto &e = graph[idx][i];
      if (e.to != par) dfs_all(e.to, idx, f(e.ndp, buff));
      e.ndp = f(e.ndp, buff);
      buff = f(buff, e.dp);
    }
  }

 public:
  Tree_DP(int V, const F f, const G1 g1, const G2 g2, T init)
      : graph(V),
        f(f),
        g1(g1),
        g2(g2),
        init(init),
        subdp(V, init),
        dp(V, init) {}

  void add_edge(int u, int v, E d, E e) {
    graph[u].emplace_back((Edge){v, d, init, init});
    graph[v].emplace_back((Edge){u, e, init, init});
  }
  void add_edge(int u, int v, E d = E()) { add_edge(u, v, d, d); }

  T build(int root) {
    dfs_sub(root, -1);
    return subdp[root];
  }

  vector<T> build_rerooting() {
    dfs_sub(0, -1);
    dfs_all(0, -1, init);
    return dp;
  }
};

signed main() {
  cin.tie(0);
  ios::sync_with_stdio(0);
  int N;
  cin >> N;
  using Pii = pair<int, int>;
  auto f = [](const Pii &vdp, const Pii &chdp) {
    Pii ret = vdp;
    ret.first += max(chdp.first - 1, chdp.second);
    ret.second += max(chdp.first, chdp.second);
    return ret;
  };
  auto g1 = [](const Pii &dp, int dat) { return dp; };
  auto g2 = [](const Pii &dp, int v) { return Pii{dp.first + 1, dp.second}; };
  Tree_DP<Pii, int> graph(N, f, g1, g2, {0, 0});
  for (int i = 0; i < N - 1; i++) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    graph.add_edge(u, v);
  }
  auto ans = graph.build(0);
  cout << max(ans.first, ans.second) << endl;
  return 0;
}