1-Vasa contre Rely - Lycée Val de Durance (Pertuis)

On the kingdom of Vasa, the imperial city is all clean, with a square fortification built with cubes all around. But every year, the Rely people whitewash the outer walls of the fortification. This is unbearable for the Vasa, who once again build a layer of cubes to hide the Rely paint.
Can we determine the size (in number of cubes) of the Vasa fortification and the quantity of paint needed to paint the exterior?