#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e5 + 10, INF = 1e9;
vector<int> e[MAXN];
int sz[MAXN], lo[MAXN], hi[MAXN], tick;
int dfs(int x, int p) {
lo[x] = tick++;
sz[x] = 1;
for (auto y : e[x]) {
if (y != p) sz[x] += dfs(y, x);
}
hi[x] = tick;
return sz[x];
}
int balance(int a, int b, int c) {
return max({a, b, c}) - min({a, b, c});
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
for (int i = 0; i < n - 1; i++) {
int x, y;
cin >> x >> y;
e[x].push_back(y);
e[y].push_back(x);
}
dfs(1, -1);
int sol = INF;
for (int x = 2; x <= n; x++) {
for (int y = x + 1; y <= n; y++) {
if (lo[x] < lo[y] && lo[y] < hi[x])
sol = min(sol, balance(sz[y], sz[x] - sz[y], n - sz[x]));
else if (lo[y] < lo[x] && lo[x] < hi[y])
sol = min(sol, balance(sz[x], sz[y] - sz[x], n - sz[y]));
else
sol = min(sol, balance(sz[x], sz[y], n - sz[x] - sz[y]));
}
}
cout << sol << '\n';
return 0;
}
