func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       string s;       cin >> s;       set<char> res;       vector<char> ans;       for (int i = 0; i < s.length(); i++) {         if (s[i] == s[i + 1]) {           i++;         } else {           char c = s[i];           res.insert(c);         }       }       for (auto i : res) cout << i;       cout <<   n ;     }   }   