#include <bits/stdc++.h>
using namespace std;
#define rep(a, b, c) for (int a = (b); a < (c); a++)
#define sz(x) int(size(x))
#define all(x) begin(x), end(x)
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;

const int LIM = 1e6 + 10;
using bs = bitset<LIM>;

void solve() {
    int n;
    cin >> n;

    vi p(n, -1);
    rep (i, 1, n) cin >> p[i], p[i]--;

    vi sub(n, 1), big(n);

    for (int i = n-1; i > 0; i--) {
        if (i > 0) {
            sub[p[i]] += sub[i];
            big[p[i]] = max(big[p[i]], sub[i]);
        }
        big[i] = max(big[i], n - sub[i]);
    }

    int rt = min_element(all(big)) - begin(big);

    vi num(n+1);

    int cap = min(n / 2, n - 1 - big[rt]) + 1;
    ll ans = big[rt] * ll(n - 1 - big[rt]);

    rep (i, 0, n) if (p[i] == rt) {
        int k = sub[i];
        num[k]++;
    }

    if (n - sub[rt] > 0) {
        int k = n - sub[rt];
        num[k]++;
    }

    {
        bs dp;
        dp[0] = 1;

        for (int k = 1; k <= n; k++) if (num[k]) {
            int up = (num[k] - 1) / 2;
            num[k] -= 2*up;
            num[2*k] += up;

            rep (_, 0, num[k])
                dp |= dp << k;
        }

        rep (i, 0, n) if (dp[i]) ans = max(ans, i * ll(n - 1 - i));
    }

    vi down(n, -1);
    for (int x = rt, y = p[x]; x != 0; x = y, y = p[x]) {
        down[y] = x;
        p[x] = -1;
    }
    
    vector<ll> dp(n, 1);

    for (int i = n-1; i >= 0; i--) {
        if (p[i] != -1) 
            dp[p[i]] += dp[i];

        if (down[i] == -1 && i != rt) ans += dp[i];
    }

    for (int i = 0; i < n; i++) {
        if (down[i] != -1) {
            dp[down[i]] += dp[i];
            ans += dp[i];
        }
    }

    ans += dp[rt];
    cout << ans << "\n";
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);

    // int t; cin >> t; while (t--)
    solve();

    return 0;
}