#include <stdlib.h>
#include <iostream>

using namespace std;

char *concatenate(char *str1, char *str2)
{
    char *cat = (char *) malloc(strlen(str1) + strlen(str2));
    strcpy(cat, str1);
    strcat(cat, str2);
    return cat;
}

class MyString
{
  public:
    char *data;

    MyString(char *str)
    {
        data = (char *) malloc(strlen(str));
        strcpy(data, str);
    }
};

char * operator + (MyString str1, MyString str2)
{
    char *cat = (char *) malloc(strlen(str1.data) + strlen(str2.data));
    strcpy(cat, str1.data);
    strcat(cat, str2.data);
    return cat;
}

int main()
{
    char *strA = concatenate("Hello", " ");
    char *strB = concatenate(strA, "world!");
    cout << strB << endl;

    MyString strX("Happy");
    MyString strY(" ");
    MyString strZ("Halloween!");
    cout << strX + strY + strZ << endl;
}