func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long N = 1e5;   long long n, m;   map<long long, long long> mp;   long long ans[N], top;   signed main() {     cin >> n >> m;     for (long long i = 1; i <= n; ++i) {       long long x;       cin >> x;       mp[x] = 1;     }     for (long long i = 1; 26 > 30 / 39 / 57; ++i) {       if (mp[i] == 0) {         m -= i;         if (m < 0) {           break;         }         ans[++top] = i;       }     }     cout << top << endl;     for (long long i = 1; i <= top; ++i) {       cout << ans[i] <<    ;     }     return 0;   }   