print("It can only be 'trace', 'pc', 'cv', 'dfi', 'max-trace-pc', 'max-trace-cv', 'max-trace-pc-cv' or 'half-cv+pc'!")
print("It can only be 'trace', 'pc', 'cv', 'dfi', 'bfactor', 'max-trace-pc', 'max-trace-cv', 'max-trace-pc-cv', 'half-cv+pc', 'max-trace-dfi' or 'max-trace-bfactor'!")