program main
character::S*4
integer::i,check
read*,S
check=0
do i=1,3
	if(S(i:i)==S(i+1:i+1))then
    	check=check+1
    else
    	check=check
    end if
end do
if(check==0)then
print*,'Good'
else
print*,'Bad'
end if
end program main