E1

void solve2()
{
    ll n, k;
    cin >> n >> k;
    vector<vl> g(n + 1);
    for (ll i = 2, p; i <= n; ++i) {
        cin >> p;
        g[p].push_back(i);
    }
    vl dcnt(n);
    ll min_leaf = LLONG_MAX / 2;
    auto dfs = [&](auto &&self, ll u, ll depth) -> void {
        dcnt[depth] += 1;
        bool is_leaf = true;
        for (auto v : g[u]) {
            self(self, v, depth + 1);
            is_leaf = false;
        }
        if (is_leaf)
            min_leaf = min(min_leaf, depth);
    };
    dfs(dfs, 1, 0);

    ll d1 = min(k, n - k), d2 = max(k, n - k);
    vl dp(d1 + 1);
    dp[0] = d2;

    ll ans = 0;
    for (ll i = 0; i <= min_leaf; ++i) {
        ll v = dcnt[i];
        vl ndp(dp);
        for (auto &x : ndp)
            x -= v;
        for (ll j = v; j <= d1; ++j)
            ndp[j] = max(ndp[j], dp[j - v]);

        swap(dp, ndp);
        for (auto &x : dp)
            if (x >= 0)
                ans = max(ans, i + 1);
    }
    cout << ans << '\n';
}