How to read a single line of txt file word by word [C++]

I need to read a single line of a given file word by word. The file is a register of exam grades by different students. In particular, for any student there is a first line formatted as follows: Then, there is a second line reporting the grades of every exam using the following format: ...

I created a class Student and want to put the grades in an array of int. I know how to read the file word by word, but I have no idea how to stop once the grades from a student are over (since I don't know how may grades any given student has beforehand). I thought to write a while repetition statement, but I have no idea what the condition could be.

Is there a way to read a line word by word and then stop reading once the line is over?

This is what I managed to write until now:

cout << "Inserisci il nome del file da analizzare: " << endl;
cin >> _filename;
fstream myfile;
myfile.open(_filename);  
if (myfile.is_open())  
{
    myfile >> _name >> _surname >> ;  //reading name and surname

}