#include?
#include?
using?namespace?std;

string?ComSubStr（string*?ln?int?n）
{
????string?longest=““;
????for?（int?j?=?60;?j?>?2;?--j）
????????for?（int?i?=?0;?i?+?j?<=?60;?++i）
????????{
????????????string?str?=?ln[0].substr（i?j）;
????????????bool?find?=?true;
????????????for?（int?k?=?1;?k?????????????????if?（ln[k].find（str）?==?string::npos）?
????????????????{
????????????????????find?=?false;
????????????????????break;
????????????????};
????????????
????????????if?（find?==?true?&&?str.size（）?>?longest.size（））longest?=?str;
????????????else?if（find?==?true?&&?str.size（）?==?longest.size（）?&&?str?????????};
????return?longest;
};
int?main（int?argc?char*?argv[]）
{
????int?cases;
????cin?>>?cases;

????int?lines;
????string?ln[10];
????for?（int?c?=?0;?c?????{
????????cin?>>?lines;
????????for?（int?i?=?0;?i?????????{
????????????cin?>>?ln[i];
????????}
????????
????????string?r?=?ComSubStr（ln?lines）;
????????if?（r?==?““）?cout?<????????else?cout?<????}
????return?0;
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2012-07-07?20:40??OJ\
?????目錄???????????0??2012-07-04?12:13??OJ\Blue?Jeans\
?????文件????????1156??2012-06-16?20:49??OJ\Blue?Jeans\1.cpp
?????文件????????7393??2012-06-05?10:47??OJ\Blue?Jeans\Blue
?????文件????????2060??2012-06-16?20:47??OJ\Blue?Jeans\main.c
?????目錄???????????0??2012-07-04?12:13??OJ\Edit?Distance\
?????文件????????5615??2012-05-21?21:21??OJ\Edit?Distance\a.out
?????文件????????1198??2012-05-21?21:21??OJ\Edit?Distance\main.c
?????目錄???????????0??2012-07-04?12:13??OJ\Independent?Task?Scheduling\
?????文件?????????737??2012-06-03?21:07??OJ\Independent?Task?Scheduling\1.c
?????文件?????????772??2012-06-03?21:40??OJ\Independent?Task?Scheduling\2.c
?????文件????????5420??2012-06-03?20:50??OJ\Independent?Task?Scheduling\a.out
?????文件?????????745??2012-06-03?20:52??OJ\Independent?Task?Scheduling\main.c
?????目錄???????????0??2012-07-04?12:13??OJ\Renting?Boats\
?????文件????????5526??2012-05-21?16:53??OJ\Renting?Boats\a.out
?????文件?????????585??2012-05-21?20:25??OJ\Renting?Boats\main.c
?????目錄???????????0??2012-07-04?12:13??OJ\Shortest?path?counting\
?????文件????????5338??2012-05-22?22:30??OJ\Shortest?path?counting\a.out
?????文件?????????444??2012-05-22?22:31??OJ\Shortest?path?counting\main.c
?????目錄???????????0??2012-07-07?20:39??OJ\StrMatch\
?????文件????????7672??2012-06-13?15:34??OJ\StrMatch\BM
?????文件????????7420??2012-06-10?22:26??OJ\StrMatch\CreateString
?????文件?????????435??2012-06-10?20:05??OJ\StrMatch\CreateString.c
?????文件????????7481??2012-06-13?15:34??OJ\StrMatch\Force
?????文件????????7487??2012-06-13?15:34??OJ\StrMatch\Horspool
?????文件????????7477??2012-06-13?15:34??OJ\StrMatch\KMP
?????文件????????7335??2012-06-13?10:51??OJ\StrMatch\Strsub
?????文件?????????509??2012-06-13?10:48??OJ\StrMatch\Strsub.c
?????目錄???????????0??2012-07-04?12:13??OJ\StrMatch\sourecfile\
?????文件????????3405??2012-06-13?15:28??OJ\StrMatch\sourecfile\BM.c
?????文件??????????55??2012-06-13?15:34??OJ\StrMatch\sourecfile\Define.h
............此處省略15個文件信息