#include <bits/stdc++.h>
using namespace std;
//~ #define int long long
#define ll long long
#define fr first
#define sc second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(),x.end()
#define sp << " " <<
#define inf 1e9
#define N 200000
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef tuple<int,int,int> tiii;
typedef pair<int,int> pii;
int n,ans=inf;
multiset<int> s1,s2;
vector<int> d(N+5,1),g[N+5];
int ff(int a,int b,int c){
return max(a,max(b,c))-min(a,min(b,c));
}
int dffs(int x,int ata){
for(auto i:g[x])
if(i!=ata)
d[x]+=dffs(i,x);
return d[x];
}
void dfs(int x,int ata){
if(!s1.empty()){
auto it=s1.lower_bound((n+d[x])/2);
if(it!=s1.end())
ans=min(ans,ff(d[x],*it-d[x],n-*it));
if(it!=s1.begin()){
it--;
ans=min(ans,ff(d[x],*it-d[x],n-*it));
}
}
if(!s2.empty()){
auto it=s2.lower_bound((n-d[x])/2);
if(it!=s2.end())
ans=min(ans,ff(d[x],*it,n-d[x]-*it));
if(it!=s2.begin()){
it--;
ans=min(ans,ff(d[x],*it,n-d[x]-*it));
}
}
s1.insert(d[x]);
for(auto i:g[x])
if(i!=ata)
dfs(i,x);
s1.erase(s1.find(d[x]));
s2.insert(d[x]);
}
void solve(){
cin >> n;
for(int i=1;i<n;i++){
int x,y;
cin >> x >> y;
g[x].pb(y);
g[y].pb(x);
}
dffs(1,0);
dfs(1,0);
cout << ans << endl;
}
int32_t main(){
//~ freopen("a.txt","r",stdin);
//~ freopen("a.txt","w",stdout);
ios_base::sync_with_stdio(false);
cin.tie(NULL);cout.tie(NULL);
int test=1;
//~ cin >> test;
while(test--) solve();
}
