polycarp work new operate system call BerOS he ask help implementation file suggestion featurethere n file hard drive name f_1 f_2 dot f_n any file contain 1 8 character inclusive all file name uniquethe file suggestion feature handle query represent string s for query s count number file contain s substre ie continuous segment character file equal s suggest file nameFor example file name readme host op beros18 query os number match file 2 file name contain os substre suggest file host beros18