text: #include <iostream>
  #include <string>
  #include <set>
  #include <algorithm>
  using namespace std;
  
  int main(int argc, char const* argv[])
  {
      string str1, str2;
      set<char> broken;
      set<char> output;
  
      cin >> str1 >> str2;
      transform(str1.begin(), str1.end(), str1.begin(), ::toupper);
      transform(str2.begin(), str2.end(), str2.begin(), ::toupper);
  
      for (int i = 0; i < str2.length(); i++) {
          broken.insert(str2[i]);
      }
  
      for (int i = 0; i < str1.length(); i++) {
          if (broken.count(str1[i]) == 0 && output.count(str1[i]) == 0) {
              output.insert(str1[i]);
              if (isalpha(str1[i])) {
                  cout << str1[i];
              } else {
                  cout << str1[i];
              }
          }
      }
      cout << endl;
  
      return 0;
  }
  