For any PRG G : $\{0,1\}\backslash$lambda $->\{0,1\}\backslash$lambda $+$l there will be many strings in $\{0,1\}\backslash$lambda $+$l that are impossible to get as output of G$.$ Let S be any such set of impossible G$-$outputs, and consider the following adversary that has S hard$-$coded:

What is the advantage of A in distinguishing LG from LG $?$ Why does an ad$-$

versary like this one not automatically break every PRG$?$