Much better. Im not an expert but, maybe you could declare int counter;
And after every cin >> you can do counter++
And after you've inputted everything. you can maybe say
1 2 3 4
if(counter !=10)
{
cout << "Error, file has less or more than 10 wheels. Check your input data file and re-run the code";
}
Im not sure if there is a better way of doing it, but this is how I would have done it, being a newbie.