func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<int> tree[500001];   bool intree[500001];   vector<int> tmp(0);   bool isleaf(int node) {     if (tree[node].size() == 1 && intree[(tree[node])[0]]) return true;     return false;   }   void DFS(int lvl, int node) {     intree[node] = true;     if (isleaf(node)) {       tmp.push_back(lvl);     }     for (int i = 0; i < tree[node].size(); i++) {       if (!intree[(tree[node])[i]]) {         DFS(lvl + 1, (tree[node])[i]);       }     }   }   int main() {     ios_base::sync_with_stdio(false);     int N;     cin >> N;     for (int i = 1; i <= N; i++) intree[i] = false;     int x, y;     for (int i = 0; i < N - 1; i++) {       cin >> x >> y;       tree[x].push_back(y);       tree[y].push_back(x);     }     intree[1] = true;     int ans = 0, c;     for (int i = 0; i < (tree[1]).size(); i++) {       tmp.clear();       DFS(0, (tree[1])[i]);       sort(tmp.begin(), tmp.end());       c = tmp.size();       for (int j = 0; j < c; j++) {         ans = max(ans, tmp[j] + c - j);       }     }     cout << ans << endl;   }   