select distinct 'Moscow'+isnull(rtrim('-'+t1),'')+isnull(rtrim('-'+t3),'')+isnull(rtrim('-'+t5),'')+isnull(rtrim('-'+t7),'')
from
(select town_to t1
from trip where town_from='Moscow') b
left join
(select town_from t2, town_to t3 from trip) b1
on t2=t1 and t3!='Moscow'
left join
(select town_from t4, town_to t5 from trip)b2
on t3=t4 and t5!=t1 and t5!='Moscow'
left join
(select town_from t6, town_to t7 from trip)b3
on t5=t6 and t7!=t1 and t7 != t4 and t7!='Moscow'
where t1='kiev' or t3='kiev' or t5='kiev' or t7='kiev'