desed
Intro :
1/-----------0-----0----0----0----0----0-----0-------0--------------------
2/-----4-4-----4----4----4----4----4-----------4-------4------------------
3/--------------------------------------------4--------4------4----------------
4/--------------------------------------------------------------------------------
1/-----------0-----0----0----0-----0-----0-------0-----------------------------
2/-----4-4-----4----4----4-----------4-------4-----4----------------------
3/--------------------------------4---------4--------4------4----------------
4/-----------