#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i = (a), _b = b;i <= _b; i++)
#define FORD(i,a,b) for(int i = (a), _b = b;i >= _b; i--)
#define int long long
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(),x.end()
#define mp make_pair
#define task "hhung"
template<class x,class y>
bool minimize(x &a,const y &b){
if(a > b){
a = b;
return true;
}else return false;
}
template<class x,class y>
bool maximize(x &a,const y &b){
if(a < b){
a = b;
return true;
}else return false;
}
typedef pair<int,int> pii;
constexpr int MAXN=1e6,MOD=1e9+7,INF=1e18;
int n,m,l,r,k,ans,res;
vector<int> adj[MAXN];
multiset<int> s1,s2;
int de[MAXN];
void dfs(int u,int p){
de[u] = 1;
for(int v : adj[u]){
if(v != p){
dfs(v,u);
de[u] += de[v];
}
}
}
void dfs1(int u,int p){
auto idx = s1.upper_bound((n + de[u])/2);
if(idx != s1.end()){
int a = de[u];
int b = *idx - de[u];
int c = n - *idx;
minimize(ans,max({a,b,c}) - min({a,b,c}));
}
if(idx != s1.begin()){
--idx;
int a = de[u];
int b = *idx - de[u];
int c = n - *idx;
minimize(ans,max({a,b,c}) - min({a,b,c}));
}
s1.insert(de[u]);
for(int v : adj[u]){
if(v != p){
dfs1(v,u);
}
}
s1.erase(s1.find(de[u]));
}
void dfs2(int u,int p){
auto idx = s2.upper_bound((n - de[u])/2);
if(idx != s2.end()){
int a = de[u];
int b = *idx - de[u];
int c = n - *idx;
minimize(ans,max({a,b,c}) - min({a,b,c}));
}
if(idx != s2.begin()){
--idx;
int a = de[u];
int b = *idx - de[u];
int c = n - *idx;
minimize(ans,max({a,b,c}) - min({a,b,c}));
}
for(int v : adj[u]){
if(v != p){
dfs2(v,u);
}
}
s2.insert(de[u]);
}
int32_t main(){
ios::sync_with_stdio(false);
cin.tie(0);cout.tie(0);
if(fopen(task".inp","r")){
freopen(task".inp","r",stdin);
freopen(task".out","w",stdout);
}
cin >> n ;
FOR(i,1,n-1){
int u,v;
cin >> u >> v;
adj[u].pb(v);
adj[v].pb(u);
}
ans = INF;
dfs(1,0);
dfs1(1,0);
dfs2(1,0);
cout << ans;
}
