Maybe someone knows how to name compounds by IUPAC ?

Explanation:

The IUPAC system of nomenclature aims to ensure

that every organic compound has a unique, unambiguous name.that the IUPAC name of any compound conveys the structure of that compound to a person familiar with the system.

One way of checking whether the name you have given to an alkane is reasonable is to count the number of carbon atoms implied by the chosen name. For example, if you named a compound 3‑ethyl-4‑methylheptane, you have indicated that the compound contains a total of 10 carbon atoms—seven carbon atoms in the main chain, two carbon atoms in an ethyl group, and one carbon atom in a methyl group. If you were to check the given structure and find 11 carbon atoms, you would know that you had made a mistake. Perhaps the name you should have written was 3‑ethyl-4,4‑dimethylheptane!