func_code_string: #include <bits/stdc++.h>   using namespace std;   long long p[2001];   long long find_size(long long x) {     if (p[x] == -1) return 1;     return 1 + find_size(p[x]);   }   void solve() {     long long n;     cin >> n;     for (long long i = 0; i < n; i++) {       long long x;       cin >> x;       if (x > 0) x--;       p[i] = x;     }     long long ans = 1;     for (long long i = 0; i < n; i++) {       ans = max(ans, find_size(i));     }     cout << ans << endl;   }   signed main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     solve();     return 0;   }   