cpp01-a.cpp(cpp01-a.txt), cpp01-b.cpp(cpp01-b.txt)
cpp02-a.cpp(cpp02-a.txt), cpp02-b.cpp(cpp02-b.txt)
cpp16-a.cpp(cpp16-a.txt), cpp16-b.cpp(cpp16-b.txt)
cpp18-a.cpp(cpp18-a.txt), cpp18-b.cpp(cpp18-b.txt)
cpp20-a.cpp(cpp20-a.txt), cpp20-b.cpp(cpp20-b.txt)