#include "bits/stdc++.h"
using namespace std;
void open_file(const string &file_name) {
if (fopen((file_name + ".inp").c_str(), "r")) {
freopen((file_name + ".inp").c_str(), "r", stdin);
freopen((file_name + ".out").c_str(), "w", stdout);
}
}
void init();
void solve();
bool multitest();
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
clock_t TIME = clock();
init();
int TEST = 1;
if (multitest()) cin >> TEST;
while (TEST--) solve();
cerr << "\nUsed: " << clock() - TIME << " ms\n\n";
}
bool multitest() {
return 0;
}
const int NM = 2e5 + 5;
int n, sz[NM], res[NM];
vector<int> adj[NM];
set<int> a[NM];
void dfs_diameter(int u, int par, int depth, pair<int,int> &ans) {
ans = max(ans, {depth, u});
for (auto &v: adj[u]) if (v != par)
dfs_diameter(v, u, depth + 1, ans);
}
pair<int,int> find_diameter() {
pair<int,int> ans = {-1, -1};
dfs_diameter(1, 1, 0, ans);
int s = ans.second;
ans = {-1, -1};
dfs_diameter(s, s, 0, ans);
return {s, ans.second};
}
void dfs(int u) {
sz[u] = 1;
for (auto &v: adj[u])
if (!sz[v]) {
dfs(v);
if (a[u].size() < a[v].size())
swap(a[u], a[v]);
for (auto &i: a[v])
a[u].insert(i);
sz[u] += sz[v];
}
auto k = a[u].upper_bound(sz[u]);
int mi = INT_MAX;
if (k != a[u].end() && mi > *k - sz[u]) {
mi = *k - sz[u];
res[u] = *k / 2;
}
if (k != a[u].begin()) {
--k;
if (mi > sz[u] - *k) {
mi = sz[u] - *k;
res[u] = *k / 2;
}
}
a[u].insert(2 * sz[u]);
}
int ac(int s) {
memset(sz, 0, sizeof(sz));
for (int i = 1; i <= n; ++i) a[i].clear();
dfs(s);
int ans = INT_MAX;
for (int i = 1; i <= n; ++i) {
vector<int> b = {res[i], sz[i] - res[i], n - sz[i]};
sort(b.begin(), b.end());
ans = min(ans, b[2] - b[0]);
}
return ans;
}
void solve() {
cin >> n;
for (int x, y, i = 1; i < n; ++i) {
cin >> x >> y;
adj[x].push_back(y);
adj[y].push_back(x);
}
auto [s, t] = find_diameter();
cout << min(ac(s), ac(t));
}
void init() {
}
