Write a program named rot_13 that shifts each letter in its argument by 13 positions in the alphabet, wrapping around at the ends.

• The program receives exactly one argument.
• Each letter is rotated by 13 positions: a becomes n, n becomes a, Z becomes M, and so on.
• Uppercase and lowercase letters are each rotated within their own range; case is preserved.
• Characters that are not letters pass through unchanged.
• Print the result followed by a newline.
• If the program does not receive exactly one argument (argc must be 2), print wrong number of arguments followed by a newline.

Write a program named rot_13 that shifts each letter in its argument by 13 positions in the alphabet, wrapping around at the ends.

• The program receives exactly one argument.
• Each letter is rotated by 13 positions: a becomes n, n becomes a, Z becomes M, and so on.
• Uppercase and lowercase letters are each rotated within their own range; case is preserved.
• Characters that are not letters pass through unchanged.
• Print the result followed by a newline.
• If the program does not receive exactly one argument (argc must be 2), print wrong number of arguments followed by a newline.