#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
signed main(){
  Int n;
  cin>>n;
  vector<vector<Int> > G(n);
  for(Int i=1;i<n;i++){
    Int x,y;
    cin>>x>>y;
    x--;y--;
    G[x].emplace_back(y);
    G[y].emplace_back(x);
  }
  vector<Int> dep(n);
  Int s=0;
  function<void(Int, Int, Int)> dfs=
    [&](Int v,Int p,Int d){
      dep[v]=d;
      for(Int u:G[v]){
        if(u==p) continue;
        dfs(u,v,d+1);
      }
      if(dep[s]<dep[v]) s=v;
    };
  dfs(0,-1,0);
  dfs(s,-1,0);
  Int ans=n-(*max_element(dep.begin(),dep.end())+1);
  cout<<ans<<endl;
  return 0;
}