function PrintLCS(b,v,i,j)
if i==0|j==0
    return;
end
if b(i,j)=='↖'
    PrintLCS(b,v,i-1,j-1);m(i)=v(i);
    else if b(i,j)=='↑'
         PrintLCS(b,v,i-1,j);
    else
         PrintLCS(b,v,i,j-1);
    end
end