func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 100002;   const int logN = 22;   vector<int> c;   map<int, int> m;   void solve() {     int n;     cin >> n;     while (n--) {       int x;       cin >> x;       m[x]++;     }     int ans = 0;     for (const pair<int, int> &x : m) {       bool f = false;       for (const int &y : c) {         if (y == x.first) {           if (x.second >= 2) {             f = true;             break;           }           continue;         }         if (y != 2 * x.first && m.find(y - x.first) != m.end()) {           f = true;           break;         }       }       if (!f) {         ans += x.second;       }     }     cout << ans << endl;   }   int main() {     int t = 1;     for (int i = 0; i <= 31; i++) {       c.push_back(1 << i);     }     while (t--) {       solve();     }     return 0;   }   