function s=larg2(x,y,x0,n)
m=length(x0);
nx=length(x);
for h=1:m
    for i=1:(nx-n)
        if (x(i)-x0(h))*(x(i+n)-x0(h))<=0
            for  k=1:(n+1)
                x1(k)=x(i+k-1);
                y1(k)=y(i+k-1);
            end
            s=larg(x1,y1,x0(h));
            x0(h)
           x1 
        end
    end
end