func_code_string: #include <bits/stdc++.h>   using namespace std;   int t;   char a[30];   int main() {     cin >> t;     while (t--) {       string s;       cin >> s;       int len = s.size(), id = 0;       for (int i = 0; i < len; i++) {         int temp = 1;         while (s[i + 1] == s[i]) {           i++;           temp++;         }         if (temp % 2 == 0) continue;         int flag = 0;         for (int j = 0; j < id; j++) {           if (a[j] == s[i]) {             flag = 1;             break;           }         }         if (!flag) a[id++] = s[i];       }       if (!id)         cout << endl;       else {         sort(a, a + id);         for (int i = 0; i < id; i++) cout << a[i];         cout << endl;       }     }     return 0;   }   