/*
 * Author       : YangDavid
 * Created Time : 2020年04月23日 星期四 00时41分05秒
 */

#include <bits/stdc++.h>
#define rep(i, n) for (int i = 1; i <= n; ++i)
using namespace std;
const int MAXN = 5050, NEG = 0xcfcfcfcf;
vector<int> G[MAXN];
int n, pool[MAXN][MAXN * 2], *dp[MAXN], *can = pool[5030] + MAXN, sz[MAXN];

void upd(int &x, int y) {
    if (x < y)
        x = y;
}
void dfs(int v, int fa, int cw) {
    sz[v] = 1;
    dp[v][cw] = 0;
    dp[v][0] = dp[v][-cw] = NEG;
    for (auto g : G[v])
        if (g != fa) {
            dfs(g, v, -cw);
            for (int i = -sz[v] - sz[g]; i <= sz[v] + sz[g]; ++i) can[i] = NEG;
            for (int i = -sz[v]; i <= sz[v]; ++i)
                if (dp[v][i] > NEG)
                    for (int j = -sz[g]; j <= sz[g]; ++j)
                        if (dp[g][j] > NEG)
                            upd(can[i + j], dp[v][i] + dp[g][j]);
            for (int i = -sz[v] - sz[g]; i <= sz[v] + sz[g]; ++i) dp[v][i] = can[i];
            sz[v] += sz[g];
        }
    for (int i = -sz[v]; i <= sz[v]; ++i) upd(dp[v][0], dp[v][i] + i * i);
}

int main() {
    scanf("%d", &n);
    rep(i, n) dp[i] = pool[i] + MAXN;
    for (int i = 1; i < n; ++i) {
        static int x, y;
        scanf("%d%d", &x, &y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    dfs(1, -1, 1);
    printf("%d\n", dp[1][0] - n);

    return 0;
}