program main
	implicit none
	integer :: a(1:5), k, TF = 0, i, j
	do i = 1, 5
		read(*, *) a(i)
	end do
	read(*, *) k
	do i = 1, 4
		do j = i+1, 5
			if(a(j) - a(i) > k) then
				TF = 1
				exit
			end if
		end do
	end do
	if(TF == 1) then
		write(*, *) ":("
	else
		write(*, *) "Yay!"
	end if
end program main