def list$\_$all$\_$routes$($remain$\_$cities, picked$\_$cities$)$:

# Your code goes here

else:

for i$,$ val in enumerate$($remain$\_$cities$)$:

new$\_$remain $=$ remain$\_$cities$[$:i$]+$ remain$\_$cities$[$i$+1$:$]$

new$\_$picked $=$ picked$\_$cities $+[$val$]$

list$\_$all$\_$routes$($new$\_$remain, new$\_$picked$)$

cities$\_$to$\_$pick $=[]$

picks $=[]$

for token in input$().$split$()$:

cities$\_$to$\_$pick.append$($token$)$

print$(\text{'}$All available routes:$\text{'})$

list$\_$all$\_$routes$($cities$\_$to$\_$pick, picks$)$