#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::pair<int, std::vector<int>> double_sweep(const std::vector<std::vector<int>> &graph) {
  std::function<std::pair<int, int>(int, int)> dfs1 = [&graph, &dfs1](int par, int ver) -> std::pair<int, int> {
    std::pair<int, int> res = {0, ver};
    for (int e : graph[ver]) {
      if (e != par) {
        std::pair<int, int> pr = dfs1(ver, e);
        ++pr.first;
        if (pr.first > res.first) res = pr;
      }
    }
    return res;
  };
  int s = dfs1(-1, 0).second;
  int diameter, t;
  std::tie(diameter, t) = dfs1(-1, s);
  std::vector<int> path{s};
  std::function<bool(int, int)> dfs2 = [&graph, &t, &path, &dfs2](int par, int ver) -> bool {
    if (ver == t) return true;
    for (int e : graph[ver]) {
      if (e != par) {
        path.emplace_back(e);
        if (dfs2(ver, e)) return true;
        path.pop_back();
      }
    }
    return false;
  };
  assert(dfs2(-1, s));
  return {diameter, path};
}

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);
  }
  cout << (n - 1) * 2 - double_sweep(graph).first << '\n';
  return 0;
}