#include <bits/stdc++.h>
void solve() {
int n;
std::cin >> n;
std::vector<std::vector<int>> adj(n + 1);
std::vector<std::array<int, 2>> edg;
for(int i = 1; i < n; i++) {
int u, v;
std::cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
edg.push_back({u, v});
}
std::vector<int> sub_tree(n + 1, 1);
std::vector<int> in(n + 1), out(n + 1);
int t = 0;
std::function<void(int, int)> dfs = [&] (int v, int p) {
in[v] = t++;
for(auto u : adj[v]) {
if(u == p) {
continue;
}
dfs(u, v);
sub_tree[v] += sub_tree[u];
}
};
dfs(1, 0);
for(int i = 1; i <= n; i++) {
out[i] = in[i] + sub_tree[i] - 1;
}
std::function<int(int, int)> in_subtree = [&] (int u, int v) {
return in[u] <= in[v] && out[u] >= out[v];
};
int ans = n + 1;
for(int u = 1; u <= n; u++) {
for(int v = u + 1; v <= n; v++) {
if(in_subtree(u, v)) {
int A = sub_tree[u] - sub_tree[v];
int B = sub_tree[v];
int C = n - sub_tree[u];
ans = std::min(ans, std::max({A, B, C}) - std::min({A, B, C}));
continue;
}
if(in_subtree(v, u)) {
int A = sub_tree[v] - sub_tree[u];
int B = sub_tree[u];
int C = n - sub_tree[v];
ans = std::min(ans, std::max({A, B, C}) - std::min({A, B, C}));
continue;
}
int A = sub_tree[u];
int B = sub_tree[v];
int C = n - (A + B);
ans = std::min(ans, std::max({A, B, C}) - std::min({A, B, C}));
}
}
std::cout << ans;
}
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int t = 1;
//std::cin >> t;
while (t--) {
solve();
}
return 0;
}
