func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, k;     while (cin >> n >> k) {       set<int> s;       int l = 0, r = 0;       int ans[200005];       int a;       while (n--) {         cin >> a;         if (s.count(a)) {           continue;         }         s.insert(a);         ans[r++] = a;         if (r > k) {           s.erase(ans[l++]);         }       }       n = min(r - l, k);       cout << n <<   n ;       while (n--) {         cout << ans[--r] <<    ;       }       cout <<   n ;     }   }   