func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 1e3 + 2;   int n;   int a[N];   map<int, int> m;   map<pair<int, int>, bool> checked;   int main() {     cin >> n;     int zero = 0;     for (int i = 0; i < n; ++i) {       scanf( %d , a + i);       if (!a[i]) zero++;       ;       m[a[i]]++;     }     sort(a, a + n);     int ans = -1;     int help1, help2, help3;     for (int i = 0; i < n; ++i)       for (int j = 0; j < n; ++j)         if (i != j) {           if (!a[i] and (!a[j])) continue;           if (checked[make_pair(a[i], a[j])]) continue;           checked[make_pair(a[i], a[j])] = true;           map<int, int> m1;           help3 = 2;           m1[a[i]]++, m1[a[j]]++;           help1 = a[i];           help2 = a[j];           while (m1[help1 + help2] < m[help1 + help2]) {             m1[help1 + help2]++;             help3++;             help2 += help1;             help1 = help2 - help1;           }           ans = max(ans, help3);         }     ans = max(ans, zero);     cout << ans;   }   