#include <iostream>
    #include <vector>
    using namespace std;

   class Set
   {
       private:
          char *num;size_t size;
       public:
          int min();
          void sort();
          void unique();
          bool find();
          Set(){}
          Set(char *str)
          {
              size = strlen(str);
              num = new char[size];
              for(int i=0; i<size; i++)
              {
                  num[i] = str[i];
              }
              //sort();
              //unique();
          }
          const Set& push(char *str)
          {
             char *temp = new char[size+strlen(str)];
             for(int i=0; i<size; i++)
             {
                  temp[i] = num[i];
             }
             temp[size] = *str;
             delete [] num;
             this->num = temp;
             this->size += strlen(str);
             return *this;
          }

          const Set operator+(const Set& s)
          {
             if(this->size != s.size)
             {
                 return NULL;
             }
             Set v;
             size = v.size + size;
             for(int i=0; i<size; i++)
             {
                 v.num[i] = num[i] + s.num[i];
             }
             return v;
          }
          friend const ostream& operator<<(ostream& os, const Set& s);
    };

const ostream& operator<<(ostream& os, const Set& s)
{
    for(int i=0; i<s.size; i++)
    {
        os << s.num[i];
    }
    return os;
}

int main(int argc, const char * argv[]) {
    // insert code here...
    std::cout << "Hello, World!n";
    char s[25] = "Hello world ";
    Set ss(s);
    char q[25] = "Holan";
    ss.push(q);
    Set sw(q);
    ss = ss + sw;
    cout << ss;
    return 0;
}