function [y]=Fsystem(u,t);
	
	K=size(u,1);
	y=zeros(J);
	a=1;
	dx=1/(J-1);

	y(1)=-(a/dx)*(u(1)-u(K-1));

	for j=2:K
		y(j)=-(a/dx)*(u(j)-u(j-1));
	end