// Akari - nna310
/*
Link: https://oj.vnoi.info/problem/coci2021_r1_papricice
*/
// #pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define G(i, a, b) for(int x, y, i = (int)(a); i <= (int)(b); ++i)
#define L(i, a, b) for(int i = (int)(a); i <= (int)(b); ++i)
#define R(i, a, b) for(int i = (int)(a); i >= (int)(b); --i)
#define F(x, c) for(auto &x : c)
#define umap unordered_map
#define pb push_back
#define ve vector
#define se second
#define fi first
#define pe pair
using namespace std;
using ll = long long;
const int N = 200005;
const ll INF = 1e17 + 5;
const int MOD = 1000000007;
int dx[4] = {1, -1, 0, 0};
int dy[4] = {0, 0, 1, -1};
int n, timer, in[N], out[N], sz[N], res = MOD;
pe<int, int> uv[N];
ve<int> g[N];
namespace sub2 {
void DFS(int u, int p) {
in[u] = ++timer;
sz[u] = 1;
for (int v : g[u]) {
if (v != p) {
DFS(v, u);
sz[u] += sz[v];
}
}
out[u] = timer;
}
void sol() {
DFS(1, -1);
L(i, 2, n) {
L(j, i + 1, n) {
if (i != j) {
if (in[i] <= in[j] && in[j] <= out[i]) {
int a = sz[j];
int b = sz[i] - a;
int c = n - sz[i];
res = min(res, max({a, b, c}) - min({a, b, c}));
} else if (in[j] <= in[i] && in[i] <= out[j]) {
int a = sz[i];
int b = sz[j] - a;
int c = n - sz[j];
res = min(res, max({a, b, c}) - min({a, b, c}));
} else {
int a = sz[i];
int b = sz[j];
int c = n - a - b;
res = min(res, max({a, b, c}) - min({a, b, c}));
}
}
}
}
}
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
auto t_start = chrono::high_resolution_clock::now();
if (fopen("papricice.inp", "r")) {
freopen("papricice.inp", "r", stdin);
freopen("papricice.out", "w", stdout);
}
cin >> n;
L(i, 1, n - 1) {
cin >> uv[i].fi >> uv[i].se;
g[uv[i].fi].pb(uv[i].se);
g[uv[i].se].pb(uv[i].fi);
}
sub2::sol();
cout << res;
auto t_end = chrono::high_resolution_clock::now();
auto elapsed = chrono::duration_cast<chrono::milliseconds>(t_end - t_start).count();
cerr << "\n\nElapsed time: " << elapsed << " ms\n";
return 0;
}
