#include <bits/stdc++.h> using namespace std; class segment_tree { private: int n; vector<int> seg; public: segment_tree(int n) : n(n), seg(2 * n, 0) {} int query(int l, int r) { int ans = 0; for (l += n, r += n + 1; l < r; l >>= 1, r >>= 1) { if (l & 1) ans = max(ans, seg[l++]); if (r & 1) ans = max(ans, seg[--r]); } return ans; } void set(int i, int x) { for (i += n, seg[i] = x, i >>= 1; i > 0; i >>= 1) { seg[i] = max(seg[2 * i], seg[2 * i + 1]); } } }; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int n, d; cin >> n >> d; vector<vector<int>> adj(n); for (int i = 1, p; i < n; ++i) { cin >> p; adj[p].push_back(i); } if (d >= n) { cout << "1\n"; return 0; } vector<int> sz(n); auto dfs_sz = [&](auto &&self, int u) -> void { sz[u] = 1; for (int &i : adj[u]) { self(self, i); sz[u] += sz[i]; } }; dfs_sz(dfs_sz, 0); auto dfs = [&](auto &&self, int u) -> vector<int> { vector<vector<int>> ch; for (int &i : adj[u]) { ch.push_back(self(self, i)); } vector<int> dp(sz[u] + 1); segment_tree st(sz[u]); auto set = [&](int i, int x) { st.set(i, dp[i] = x); }; auto max_suff = [&](int i) { return st.query(i, sz[u] - 1); }; for (auto &ndp : ch) { vector<int> qvals(ndp.size()); for (int i = 0; i < ndp.size(); ++i) { if (max(i + 1, d - i) < dp.size() - 1) { qvals[i] = max_suff(max(i + 1, d - i)); } } vector<int> suff_ndp(ndp.size()); suff_ndp.back() = ndp.back(); for (int i = ndp.size() - 2; i >= 0; --i) { suff_ndp[i] = max(ndp[i], suff_ndp[i + 1]); } for (int i = 0; i < ndp.size() - 1; ++i) { if (max(i, d - i) < ndp.size()) { set(i, dp[i] + suff_ndp[max(i, d - i)]); } } for (int i = 0; i < ndp.size(); ++i) { set(i, max(dp[i], ndp[i])); } for (int i = 0; i < ndp.size(); ++i) { if (max(i + 1, d - i) < dp.size() - 1) { set(i, max(dp[i], qvals[i] + ndp[i])); } } } dp[0] = max(dp[0], (d < sz[u] ? dp[d] : 0) + 1); for (int i = dp.size() - 1; i >= 1; --i) { dp[i] = dp[i - 1]; } dp[0] = 0; return dp; }; vector<int> dp = dfs(dfs, 0); cout << *max_element(dp.begin(), dp.end()) << '\n'; }