func_code_string: #include <bits/stdc++.h>   using namespace std;   char str[50];   pair<int, pair<int, char*> > p[100001];   long long c[100005];   vector<int> ans;   map<int, int> mp;   int main() {     std::ios::sync_with_stdio(false);     long long n, m, x;     cin >> n >> m;     for (int i = 0; i < n; i++) {       cin >> c[i];     }     sort(c, c + n);     int j = 1;     while (m > 0 && j < c[0]) {       m = m - j;       if (m >= 0) ans.push_back(j);       j++;     }     c[n] = 1000000002;     if (m > 0) {       for (int i = 0; i < n; i++) {         j = c[i] + 1;         while (m > 0 && j < c[i + 1]) {           m = m - j;           if (m >= 0) ans.push_back(j);           j++;         }         if (m <= 0) break;       }     }     cout << ans.size() <<   n ;     for (int i = 0; i < ans.size(); i++) cout << ans[i] <<    ;     return 0;   }   