题目描述

PDF

输入格式

AS shown in the PDF.

输出格式

AS shown in the PDF.

样例

6 
abc 
acb 
cab 
cba 
bac 
bca 

3 

11 
alerts 
alters 
artels 
estral 
laster 
ratels 
salter 
slater 
staler 
stelar 
talers 

8 

6 
ates 
east 
eats 
etas 
sate 
teas 

4 

提示

sourced from 2019 ACM Southeast USA regional（10小时马拉松赛）

by QLU_杨光耀