#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef int _loop_int;
#define REP(i,n) for(_loop_int i=0;i<(_loop_int)(n);++i)
#define FOR(i,a,b) for(_loop_int i=(_loop_int)(a);i<(_loop_int)(b);++i)
#define FORR(i,a,b) for(_loop_int i=(_loop_int)(b)-1;i>=(_loop_int)(a);--i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

#define CHMIN(a,b) a=min((a),(b))
#define CHMAX(a,b) a=max((a),(b))

// mod
const ll MOD = 1000000007ll;
#define FIX(a) ((a)%MOD+MOD)%MOD

// floating
typedef double Real;
const Real EPS = 1e-11;
#define EQ0(x) (abs(x)<EPS)
#define EQ(a,b) (abs(a-b)<EPS)
typedef complex<Real> P;

int n;
vi g[125252];
int dist[125252];

void dfs(int p, int bef, int d){
  dist[p] = d;
  for(int to : g[p])if(to != bef){
    dfs(to,p,d+1);
  }
}

int main(){
  scanf("%d",&n);
  REP(i,n-1){
    int a,b;
    scanf("%d%d",&a,&b);--a;--b;
    g[a].push_back(b);
    g[b].push_back(a);
  }
  dfs(0,-1,0);
  int x = max_element(dist,dist+n) - dist;
  dfs(x,-1,0);
  int r = *max_element(dist,dist+n)+1;
  printf("%d\n",n-r);
  return 0;
}