func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 150, M = 150, OO = 0x3f3f3f3f;   int n, arr[2005], temp, ans;   void DFS(int u) {     temp++;     if (arr[u] == -1) return;     DFS(arr[u]);   }   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; ++i) {       scanf( %d , arr + i);     }     for (int i = 1; i <= n; ++i) {       temp = 0;       DFS(i);       ans = max(ans, temp);     }     printf( %d n , ans);     return 0;   }   