#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9 + 69;
bool ckmin(int& a, int b) {
return a > b? a = b, true : false;
}
int n;
vector<int> adj[200005];
multiset<int> ancestor, other;
int d[200005];
int res = inf;
void dfs(int u, int par = -1) {
d[u] = 1;
for (int& v : adj[u]) if (v != par) {
dfs(v, u);
d[u] += d[v];
}
}
void DFS(int u, int par = -1) {
// 2 node la to tien cua nhau
if (u != 1) {
auto it = ancestor.lower_bound(n+d[u]);
if (it != ancestor.end()) {
int s = *it; s /= 2;
int part_one = d[u];
int part_two = n - s;
int part_three = s - d[u];
int mx = max({part_one, part_two, part_three});
int mn = min({part_one, part_two, part_three});
ckmin(res, mx - mn);
}
if (it != ancestor.begin()) {
-- it;
int s = *it; s /= 2;
int part_one = d[u];
int part_two = n - s;
int part_three = s - d[u];
int mx = max({part_one, part_two, part_three});
int mn = min({part_one, part_two, part_three});
ckmin(res, mx - mn);
}
}
// 2 node khong phai to tien cua nhau
if (u != 1) {
auto it = other.lower_bound(n-d[u]);
if (it != other.end()) {
int s = *it; s /= 2;
int part_one = d[u];
int part_two = s;
int part_three = n - d[u] - s;
int mx = max({part_one, part_two, part_three});
int mn = min({part_one, part_two, part_three});
ckmin(res, mx - mn);
}
if (it != other.begin()) {
-- it;
int s = *it; s /= 2;
int part_one = d[u];
int part_two = s;
int part_three = n - d[u] - s;
int mx = max({part_one, part_two, part_three});
int mn = min({part_one, part_two, part_three});
ckmin(res, mx - mn);
}
}
ancestor.insert(2*d[u]);
for (int& v : adj[u]) if (v != par)
DFS(v, u);
ancestor.erase(ancestor.find(2*d[u]));
other.insert(2*d[u]);
}
int main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n;
for (int i = 1; i < n; ++ i) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
dfs(1, -1);
DFS(1, -1);
cout << res;
return 0;
}
