#include <bits/stdc++.h>
using namespace std;
using i64 = long long;

vector<vector<int>> g;

int last;

void dfs(int v, int f) {
  last = v;
  for(int to : g[v]) {
    if(f == to) continue;
    dfs(to, v);
  }
}

vector<int> dist;

int main() {
  int N;
  cin >> N;
  g.resize(N);
  vector<int> a(N - 1), b(N - 1);
  for(int i = 0;i < N - 1;i++) {
    cin >> a[i] >> b[i];
    a[i]--;
    b[i]--;
    g[a[i]].push_back(b[i]);
    g[b[i]].push_back(a[i]);
  }
  dfs(0, -1);
  dist.resize(N, -1);

  queue<int> que;
  dist[last] = 0;
  que.push(last);

  while(!que.empty()) {
    int v = que.front();
    que.pop();
    for(int t : g[v]) {
      if(dist[t] == -1) {
        dist[t] = dist[v] + 1;
        que.push(t);
      }
    }
  }

  int vv = *max_element(begin(dist), end(dist));
  vv++;
  cout << N - vv << endl;
}