func_code_string: #include <bits/stdc++.h>   using namespace std;   const int mod = 1e9 + 7;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     map<long long, long long> mp;     deque<long long> a;     long long n, k, d, m = 0;     cin >> n >> k;     for (auto i = 0; i < n; i++) {       cin >> d;       if (!mp[d]) {         mp[d] = 1;         a.push_front(d);         if (a.size() > k) {           mp[a.back()] = 0;           a.pop_back();         }       }     }     cout << a.size() <<   n ;     for (const auto val : a) cout << val <<    ;     return 0;   }   