#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define FOR(i,l,r) for(int i = (l), _r = (r); i <= _r; i++)
#define FORN(i,r,l) for(int i = (r), _l = (l); i >= _l; i--)
#define endl '\n'
#define sz(x) (int)x.size()
#define fi first
#define se second
#define pb push_back
#define all(v) (v).begin(),(v).end()
#define MASK(x) (1LL << (x))
#define BIT(x,i) (((x) >> (i)) & 1)
#define ins insert
#define segleft id<<1
#define segright id<<1|1
#define ci1(a) cin >> a
#define ci2(a, b) cin >> a >> b
#define ci3(a, b, c) cin >> a >> b >> c
#define ci4(a, b, c, d) cin >> a >> b >> c >> d
const int N = 2e5+5;
vector<int> edge[N];
int num[N];
int n, ans = INT_MAX;
multiset<int> st;
void dfs(int u, int p) {
num[u] = 1;
for(int v : edge[u]) if (v!=p) {
dfs(v, u);
num[u] += num[v];
}
}
void dfsth1(int u, int p) {
auto idx = st.upper_bound(((n+num[u])/2));
if (idx != st.end()) {
int a = num[u];
int b = *idx - num[u];
int c = n - *idx;
ans = min(ans, max({a,b,c}) - min({a,b,c}));
}
if (idx != st.begin()) {
--idx;
int a = num[u];
int b = *idx - num[u];
int c = n - *idx;
ans = min(ans, max({a,b,c}) - min({a,b,c}));
}
st.insert(num[u]);
for(int v : edge[u]) if (v!=p) {
dfsth1(v, u);
}
st.erase(st.find(num[u]));
}
void dfsth2(int u, int p) {
auto idx = st.upper_bound(((n-num[u])/2));
if (idx != st.end()) {
int a = num[u];
int b = *idx;
int c = n - a - b;
ans = min(ans, max({a,b,c}) - min({a,b,c}));
}
if (idx != st.begin()) {
--idx;
int a = num[u];
int b = *idx;
int c = n - a - b;
ans = min(ans, max({a,b,c}) - min({a,b,c}));
}
for(int v : edge[u]) if (v!=p) {
dfsth2(v, u);
}
st.insert(num[u]);
}
void Semicolon() {
cin >> n;
FOR(i, 1, n-1) {
int u,v; cin >> u >> v;
edge[u].pb(v);
edge[v].pb(u);
}
dfs(1, 0);
st.clear();
dfsth1(1, 0);
st.clear();
dfsth2(1, 0);
cout << ans << endl;
}
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0);
//freopen("", "r", stdin);
//freopen("", "w", stdout);
//freopen("input.txt", "r", stdin);
int t = 1;
//cin >> t;
while(t--) Semicolon();
return 0;
}
