combine .......\1.txt .......\10.txt .......\2.txt .......\3.txt .......\4.txt .......\5.txt .......\6.txt .......\7.txt .......\8.txt .......\9.txt .......\a.out .......\atoi .......\atoi.c .......\com .......\com.c .......\data.txt .......\exatoi.c