#include <iostream>
#include <utility>
#include <vector>
using namespace std;
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define REP(i, n) FOR(i,0,n)

#include <cassert>
#include <cstdlib>
#include <utility>
#include <vector>

// Rerooting
// Reference:
// - https://atcoder.jp/contests/abc222/editorial/2749
// - https://null-mn.hatenablog.com/entry/2020/04/14/124151
template <class Edge, class St, class Ch, Ch (*merge)(Ch, Ch), Ch (*f)(St, int, Edge),
          St (*g)(Ch, int), Ch (*e)()>
struct rerooting {
    int n_;
    std::vector<int> par, visited;
    std::vector<std::vector<std::pair<int, Edge>>> to;
    std::vector<St> dp_subtree;
    std::vector<St> dp_par;
    std::vector<St> dpall;
    rerooting(const std::vector<std::vector<std::pair<int, Edge>>> &to_)
        : n_(to_.size()), par(n_, -1), visited(n_, 0), to(to_) {
        for (int i = 0; i < n_; ++i) dp_subtree.push_back(g(e(), i));
        dp_par = dpall = dp_subtree;
    }

    void run_connected(int root) {
        if (visited[root]) return;
        visited[root] = 1;
        std::vector<int> visorder{root};

        for (int t = 0; t < int(visorder.size()); ++t) {
            int now = visorder[t];
            for (const auto &edge : to[now]) {
                int nxt = edge.first;
                if (visited[nxt]) continue;
                visorder.push_back(nxt);
                visited[nxt] = 1;
                par[nxt] = now;
            }
        }

        for (int t = int(visorder.size()) - 1; t >= 0; --t) {
            int now = visorder[t];
            Ch ch = e();
            for (const auto &edge : to[now]) {
                int nxt = edge.first;
                if (nxt == par[now]) continue;
                ch = merge(ch, f(dp_subtree[nxt], nxt, edge.second));
            }
            dp_subtree[now] = g(ch, now);
        }

        std::vector<Ch> left;
        for (int now : visorder) {
            int m = int(to[now].size());
            left.assign(m + 1, e());
            for (int j = 0; j < m; j++) {
                int nxt = to[now][j].first;
                const St &st = (nxt == par[now] ? dp_par[now] : dp_subtree[nxt]);
                left[j + 1] = merge(left[j], f(st, nxt, to[now][j].second));
            }
            dpall[now] = g(left.back(), now);

            Ch rprod = e();
            for (int j = m - 1; j >= 0; --j) {
                int nxt = to[now][j].first;
                if (nxt != par[now]) dp_par[nxt] = g(merge(left[j], rprod), now);

                const St &st = (nxt == par[now] ? dp_par[now] : dp_subtree[nxt]);
                rprod = merge(f(st, nxt, to[now][j].second), rprod);
            }
        }
    }

    void run() {
        for (int i = 0; i < n_; ++i) {
            if (!visited[i]) run_connected(i);
        }
    }

    const St &get_subtree(int root_, int par_) const {
        if (par_ < 0) return dpall.at(root_);
        if (par.at(root_) == par_) return dp_subtree.at(root_);
        if (par.at(par_) == root_) return dp_par.at(par_);
        std::exit(1);
    }
};

using Subtree = pair<int, int>; // (塗った、塗らない)
using Child = pair<int, int>;
struct Edge {};
Child e() { return {0, 0}; }
Child merge(Child x, Child y) { return {max(x.first, x.second) + max(y.first, y.second), x.second + y.second}; }
Child f(Subtree x, int, Edge) { return x; }
Subtree g(Child x, int) { return {1 + x.second, max(x.first, x.second)}; }


int main() {
    cin.tie(nullptr), ios::sync_with_stdio(false);
    int N;
    cin >> N;
    vector<vector<pair<int, Edge>>> to(N);
    REP(e, N - 1) {
        int a, b;
        cin >> a >> b;
        --a, --b;
        to.at(a).emplace_back(b, Edge{});
        to.at(b).emplace_back(a, Edge{});
    }

    rerooting<Edge, Subtree, Child, merge, f, g, e> tree(to);
    tree.run();

    int ret = N;
    REP(i, N) ret = min(ret, tree.dpall.at(i).first);

    cout << ret << '\n';
}