#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2005;
int n;
vector<int> adj[MAXN];
int parent[MAXN], sz[MAXN];
int tin[MAXN], tout[MAXN], timer;
void dfs(int u, int p) {
parent[u] = p;
sz[u] = 1;
tin[u] = ++timer;
for (int v : adj[u]) {
if (v == p) continue;
dfs(v, u);
sz[u] += sz[v];
}
tout[u] = timer;
}
bool ok(int u, int v) {
return tin[u] <= tin[v] && tout[v] <= tout[u];
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
//freopen("a.inp","r",stdin);
//freopen("a.out","w",stdout);
cin >> n;
for (int i = 1; i < n; i++) {
int x, y;
cin >> x >> y;
adj[x].push_back(y);
adj[y].push_back(x);
}
dfs(1, 0);
int ans = n;
for (int u = 2; u <= n; u++) {
for (int v = u + 1; v <= n; v++) {
int a, b, c;
if (ok(u, v)) {
a = sz[v];
b = sz[u] - sz[v];
c = n - sz[u];
}
else if (ok(v, u)) {
a = sz[u];
b = sz[v] - sz[u];
c = n - sz[v];
}
else {
a = sz[u];
b = sz[v];
c = n - sz[u] - sz[v];
}
int mx = max({a, b, c});
int mn = min({a, b, c});
ans = min(ans, mx - mn);
}
}
cout << ans << "\n";
}
