#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl "\n"
#define ff first
#define ss second
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
const int N = 2e5 + 5;
int ans = 1e18,n; set<int> s[N];
vector<int> adj[N],sz(N);
void merge(set<int> &a,set<int> &b){
if(a.size() < b.size()) swap(a,b);
for(int x : b){
a.insert(x);
}
}
void dfs(int node,int p){
sz[node] = 1;
for(int go : adj[node]){
if(go == p) continue;
dfs(go,node);
sz[node] += sz[go];
merge(s[node],s[go]);
}
s[node].insert(sz[node]);
auto f = s[node].upper_bound(sz[node] / 2);
if(f != s[node].end()){
vector<int> tmp = {*f,sz[node] - *f,n - sz[node]};
sort(tmp.begin(),tmp.end());
ans = min(ans,tmp[2] - tmp[0]);
}
if(f != s[node].begin()){
auto s = prev(f);
vector<int> tmp = {*s,sz[node] - *s,n - sz[node]};
sort(tmp.begin(),tmp.end());
ans = min(ans,tmp[2] - tmp[0]);
}
}
void solve(){
cin >> n;
for(int i = 1; i < n; i++){
int a,b; cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
dfs(1,0);
cout << ans << endl;
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
while(t--)
solve();
return 0;
}
