program answer
  implicit none

  integer :: a, b, c, d, e, k

  read(*,*) a
  read(*,*) b
  read(*,*) c
  read(*,*) d
  read(*,*) e
  read(*,*) k
  if(abs(a-b)<=k .and. abs(a-c)<=k .and. abs(a-d)<=k .and. abs(a-e)<=k) then
     if(abs(b-c)<=k .and. abs(b-d)<=k .and. abs(b-e)<=k .and.abs(c-d)<=k) then
        if( abs(c-e)<=k .and. abs(d-e)<=k) then
           write(*,*) 'Yay!'
        else
           write(*,*) ':('
        end if
     else
        write(*,*) ':('
     end if
  else
     write(*,*) ':('
  end if

  stop
 end program answer
