Problem with subdomains

Hi everyone.
Im novice in freefem and i need some help.
I want to define a complicate domain.
this domain is in the following picture.

The code i choose is
“”"int NbNoeuds = 120;
real kAir=1;
real kObjet=10;
// Définition du carré

border b1(t=0,1){x=t;y=0;label=1;};
border b2(t=0,1){x=1;y=t;label=1;};
border b3(t=0,1){x=1-t;y=1;label=1;};
border b4(t=0,1){x=0;y=1-t;label=1;};

The coordonate of the small circles are (±0.75, ±0.75)

thank you

A very close example

Th-four.edp (1.9 KB)

the graphic is: