func_code_string: #include <bits/stdc++.h>   using namespace std;   const long int z = 1000000007;   long long int h[1000009], a[1000009];   int main() {     ios_base::sync_with_stdio(0);     cin.tie(NULL);     cout.tie(NULL);     vector<pair<string, string> > p;     std::set<int> myset;     std::set<int>::iterator it;     long long int n, m, i, x = 0, y, v, j, d, c, k = 0, max = 0, sum = 0,                            flag = 0;     cin >> n >> m;     for (i = 0; i < n; i++) {       cin >> x;       myset.insert(x);     }     x = 1;     while (sum <= m) {       it = myset.begin();       if (*it != x) {         sum += x;         if (sum <= m) {           a[k] = x;           k++;         }       } else {         myset.erase(it);       }       x++;     }     cout << k << endl;     for (i = 0; i < k; i++) cout << a[i] <<    ;   }   