Федосов - Лабораторная работа #2

You still don't have a proper formatting. You have to increase indentation level, when you enter a new scope. Like,

    class Length {
        int x;
    };

Not

    class Length {
    int x;
    };

And, BTW, the folder is named `Includes` (with capital `I`), where it should be named all lowercase (most file systems are case sensitive)