insert 89 89 city_01
insert 75 75 city_02
list 1
list 2
list 3
makenull
list 1
list 2
list 3
insert 89 89 city_02
insert 75 75 city_04
insert 42 42 city_01
insert 25 25 city_07
list 1
list 2
list 3
insert 18 18 city_04
list 1
list 2
list 3
find 2 25
list 1
list 2
list 3
find 3 city_07
list 1
list 2
list 3
find 1 89
list 1
list 2
list 3
remove 1 25
list 1
list 2
list 3
remove 2 72
list 1
list 2
list 3
remove 3 city_09
list 1
list 2
list 3