Study the following arrangement carefully and answer the questions given below:
M 5 $ P 6 W ! R 5 B 4 7 H @ O 7 # V  Y  N & * A   8 J ! Q  U % G L 7 F  C E   & X  Z  S 1 © 3 K β

Q:

How many such numbers are there in the above arrangement each of which is either immediately followed or preceded by a letter but not both?  

• 1
  Three
• 2
  More than five
• 3
  One
• 4
  Two