function lya=lyapunov(y,m,N)
E=2.05;%threshold value
t0=2; %the begining place
k=1;kl=t0;
while(k<N)
    kk=K(y,m,N,k1);
    n=min(N-k1,N-kk);
    L1(k)=d(y(kl ,:)-y(kk,:),m);
    for i=l:n
        dd=d(y(kl+i,:)-y(kk+i,:),m);
        if(dd>E)
                kl=kl+i;
                L2(k)=dd;
                k=k+l;
                break
        end
    end
      if(i>n-1)
        break;
      end 
end
 k=k-1;
 lya=0;
     for i=l:k
         lya=lya+log(L2(i)/L1(i))
     end
 lya=lya/(kl-t0);