func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long M = 100100 * 5;   const long long N = 50005;   long long m, b, k;   map<long long, long long> fre;   int v1[M], mmax;   int main() {     ios::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     cin >> m;     for (int i = 0; i < m; i++) {       cin >> b;       fre[b]++;     }     for (int i = 0; i < N; i++) {       if (fre[i]) v1[k] = i, k++, fre[i]--, mmax = max(mmax, i);     }     for (int i = mmax - 1; i >= 0; i--) {       if (fre[i]) v1[k] = i, k++;     }     cout << k << endl;     for (int i = 0; i < k; i++) cout << v1[i] <<    ;   }   