cin                  Input Stream


        In C++, cin corresponds to stdin. You can work with cin like
    this: cin>>x, where x is a data type or object, and >> is the
    overloaded right shift operator, also called the extraction
    operator in C++. Note that cin is also an alias for
    istream_withassign.

    Note:   You can also chain the use of << and >> like this:
            cout << "This is the value of x:" << x << "\n"; You do not
            need to worry about the type of the arguments you pass
            -- the << and >> operators are overloaded to handle all
            standard types, and you can even overload them for your own
            types.

            In addition, you can format input with the cin.setf()
            member function -- see Formatting for more details.