func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     int arr[n];     for (int i = 0; i < n; i++) cin >> arr[i];     sort(arr, arr + n, greater<int>());     deque<int> d;     d.push_front(arr[0]);     int i;     for (i = 1; i < n; i++) {       if (arr[i] != arr[0]) break;     }     while (i < n) {       int a = arr[i];       d.push_back(a);       if (arr[i] == arr[i + 1]) d.push_front(a);       for (; i < n; i++) {         if (arr[i] != a) break;       }     }     cout << d.size() << endl;     while (d.size() > 0) {       cout << d.front() <<    ;       d.pop_front();     }   }   