第n个质数
.........\a8.c
.........\a8.dsp
.........\a8.dsw
.........\a8.ncb
.........\a8.opt
.........\a8.plg
.........\data.txt
.........\Debug
.........\.....\a8.exe
.........\.....\a8.ilk
.........\.....\a8.obj
.........\.....\a8.pch
.........\.....\a8.pdb
.........\.....\vc60.idb
.........\.....\vc60.pdb