real om=50;
int n =4;

border a(t=0,1) {x=5; y=1+2*t;}
border b(t=0,1) {x=5-2*t; y=3;}
border c(t=0,1) {x=3-2*t; y=3-2*t;}
border d(t=0,1) {x=1-t; y=1;}
border f(t=0,1) {x=0; y=1-t;}
border g(t=0,1) {x=t; y=0;}
border h(t=0,1) {x=1+4*t; y=t;}

border e1(t=2*pi, 0) {x=1.5+0.08*cos(t); y=0.1+0.3 +0.14*sin(t);}
border e2(t=2*pi, 0) {x=2.5+0.08*cos(t); y=0.1+0.6 +0.14*sin(t);}
border e3(t=2*pi, 0) {x=3.5+0.08*cos(t); y=0.1+0.85+0.14*sin(t);}
border e4(t=2*pi, 0) {x=4.5+0.08*cos(t); y=0.1+1.1 +0.14*sin(t);}

mesh th=buildmesh(a(3*n) + b(3*n) + c(6*n) + d(2*n) + f(2*n) + 
g(2*n) + h(6*n) + e1(2*n) + e2(2*n) + e3(2*n) + e4(2*n));
plot(th, wait=1);

fespace Vh(th, P1);
fespace Ph(th, P0);

Ph ff = (sin(x-0.45)^2 + cos(y-0.45)^2)<0.45; 

Vh u, v;
problem concert(u, v) = 
	int2d(th)(om*u*v - dx(u)*dx(v)-dy(u)*dy(v))
       + int2d(th)(-ff*v)
       + on(a,b,c,d,f,g,h,e1,e2,e3,e4,u=0);

concert;
plot(u,wait=1);
 

th=adaptmesh(th,u,err=0.01);
plot(th, wait=1);
concert;
plot(u,wait=1);