func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 5e5 + 10;   vector<int> g[N];   bool visited[N];   vector<int> z;   void dfs(int v, int depth) {     visited[v] = true;     bool isLeaf = true;     for (auto& i : g[v]) {       if (!visited[i]) {         dfs(i, depth + 1);         isLeaf = false;       }     }     if (isLeaf) z.push_back(depth);   }   int main() {     int n;     scanf( %d , &n);     for (int i = 0; i < n - 1; i++) {       int a, b;       scanf( %d %d , &a, &b);       g[a].push_back(b);       g[b].push_back(a);     }     int ans = -1;     visited[1] = true;     for (auto& j : g[1]) {       z.clear();       dfs(j, 0);       sort(z.begin(), z.end());       int prev = z[0], cur = -1;       for (int i = 1; i < z.size(); i++) {         cur = max(z[i], prev + 1);         prev = cur;       }       ans = max(ans, prev + 1);     }     printf( %d n , ans);   }   