Please add your content into the section folder. It should have the following structure:

(obviously, you should replase sections and subsectionX with the section name and the subsection name)

$ tree OCRudoku-first-defense/

OCRudoku-first-defense/
├── main.txt
├── README.txt
└── sections
    ├── section1
    │   └── section1.tex
    └── section2
        ├── subsection1
        │   └── subsection2.tex
        └── subsection2
            └── subsection2.tex