with Text_Io;Procedure B is Use Ascii,Text_Io;Subtype C Is Character;procedure F(H:C)is A:C;begin Get(A);if C'Pos(a)rem 4 in 1..2 then if C'Pos(h)/6/=C'Pos(A)/6 Then Put("failed at: "&A&Get_Line&Lf);elsif End_Of_Line Then Put("yes"&Lf);end if;elsif End_Of_Line then Put("failed at: EOL"&Lf);else F(A);F(H);end If;end;begin F(Lf);end;