function K = RelevantIndices(h)

i = round(sqrt(-1));

[x,y] = ndgrid(0:floor(1/h));
z = x + sqrt(-1)*y;
z = z(abs(z)<1/h);

z = unique([z; z+1; z+i; z+1+i]);
K = [];
for p = 1:3
  for q = 1:3;
    K = unique([K; z-p-q*i]);
  end
end