#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>

#include <iostream>
#include <complex>
#include <string>
#include <algorithm>
#include <numeric>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>

#include <functional>
#include <cassert>

typedef long long ll;
using namespace std;

#ifndef LOCAL
#define debug(x) ;
#else
#define debug(x) cerr << __LINE__ << " : " << #x << " = " << (x) << endl;

template <typename T1, typename T2>
ostream &operator<<(ostream &out, const pair<T1, T2> &p) {
  out << "{" << p.first << ", " << p.second << "}";
  return out;
}

template <typename T>
ostream &operator<<(ostream &out, const vector<T> &v) {
  out << '{';
  for (const T &item : v) out << item << ", ";
  out << "\b\b}";
  return out;
}
#endif

#define mod 1000000007 //1e9+7(prime number)
#define INF 1000000000 //1e9
#define LLINF 2000000000000000000LL //2e18
#define SIZE 200010

vector<int> tree[SIZE];

pair<int,int> dfs(int now, int prev = -1){
  pair<int,int> res = {0, now};

  for (int to : tree[now]) {
    if (to != prev) {
      res = max(dfs(to, now), res);
    }
  }

  res.first += 1;
  return res;
}

int main(){
  int n;

  cin >> n;

  for(int i=0;i<n-1;i++){
    int a, b;
    cin >> a >> b;
    a--; b--;
    tree[a].push_back(b);
    tree[b].push_back(a);
  }

  auto p = dfs(0);
  p = dfs(p.second);

  cout << n - p.first << endl;

  return 0;
}