function k = UK_appr(x,y,T)
k =  strcmp(x,y);
for n=1:min(length(x),length(y))
  k = k + Kn_appr(x,y,n,T);
end
return


function k = Kn_appr(x,y,n,T)
global ALF Kcounts
nalf = length(ALF);
cnt = 0;
acc = 0;
N = 2^n * n ^ (n*nalf);
%while 1
for t=1:T
  A = randDFA(ALF,n);
  bx = run_dfsa(A,x);
  by = run_dfsa(A,y);

  acc = acc + bx*by;
  cnt = cnt + 1;
  p = acc/cnt;
  k1 = p*N;
  
  %fprintf('trial = %d;  k0 = %d     k1 = %1.5f    rat = %1.9f    \n',cnt,k0,k1,k1/k0);
  %fprintf('trial = %d;  k1 = %d    \n',cnt,round(k1));  
end
k = k1;
return