#include<bits/stdc++.h>
using namespace std;
class str_plus
{
    int len;
    char *p;
public:
    str_plus(char *str);
    str_plus();
    str_plus operator+(char *s);
    str_plus operator=(str_plus ob);
    void show();

};
str_plus::str_plus()
{
    len=1;
    p=(char *)malloc(sizeof(char)*len);
    strcpy(p,"*");
}
str_plus::str_plus(char *str)
{
    len=strlen(str)+1;
    p=(char *)malloc(sizeof(char)*len);
    strcpy(p,str);

}
str_plus str_plus::operator+(char *s)
{
    p=(char *)realloc(p,sizeof(char)*strlen(s));
    strcat(p,s);
    return *this;
}
str_plus str_plus::operator=(str_plus ob)
{
    p=(char *)realloc(p,sizeof(char)*strlen(ob.p));
    strcpy(p,ob.p);
    return *this;
}
void str_plus::show()
{
    cout<<p<<"\n";
}
int main()
{
    int n,k;
    str_plus ob1("mahmud"),ob2("mushi"),ob3();
    //ob2=ob1+"is good ";
    ob1=ob1+" is a good";
    ob2=ob2+" is a good boy";
   // ob3=ob3+"hello  world"
   ///this shows error
    ob2.show();
    ob1.show();
    ///after "is a good" unknown random chars
    return 0;
}