import sys
#   Read a file specified by the first command line argument.
#   Primt the number of characters in the file and then the file itself.

if len(sys.argv) < 2:
    print("Usage: infile_3.py <filename>")
    sys.exit(1) # Exit with an error code

filename = sys.argv[1]

#   The default mode is "r" but explicitly specifying the mode as "r" provides clarity of intention.
with open(filename, mode="r") as f:
	s = f.read()
	print(f"Number of characters in the file: {len(s)}\n")
	print(s)